Earth\'s Mineral Resources
Descripción
Mineral Resources
Contents • • • • • • •
Periodic Table of Elements Mineral Resources Standard classification of metals Classification of deposit types (14) Non-metals & Industrial Minerals Mineral Collecting Fireworks
• Gems & Gemstones • Gem deposits • Gems in Canada
Periodic Table of Elements • • • • • •
Metals (copper) Non metals (oxygen) Alkali metals (sodium) Alkaline earth metals (magnesium) Halogens (chlorine) Noble gases (helium)
Name of elements • Discovered one by one • Some from the locality where they were found first (Yttrium from Ytterby, Sweden) • Greek/ Latin roots in most names • Hydrogen= ydor, hydro (water) + gene (creating) • Helium is the Greek word for the Sun, because it was discovered there by the spectrum
• Lithium= Greek word for stone, because it comes from rocks not plants (like its neighbors on the Table) • Oxygen= acid creator (erroneously thought) • Chlorine= means green-yellow • Nickel= from Old Nick meaning the Devil, because you get no copper. They thought the reddish mineral would give Cu on smelting
• Molybdenum= meaning “lead” or “a soft, black substance that can be used for writing” • Antimony= “instead of by itself” or not found by itself, always mixed with other minerals • Iodine= the color of violet (flower) • Lanthanum= “easily missed” because it is hidden among other minerals • Gold= yellow
• Platinum= “small silver” because it is white and usually found with gold • Uranium= from planet Uranus, discovered at about the same time as the element
The Elements • Arranged according to atomic number (size of atom) • From element # 1 to element # 26 (Iron) manufactured by our Sun (the star) • All higher than # 26 manufactured by supernova explosion of pre-existing stars • Therefore, our solar system is second generation star system (attractive to aliens?)
The Periodic Table • • • • •
Tabular arrangement of elements Atomic number is # of protons in the nucleus Rows called periods, columns are groups 18 columns, 7 rows with a double row below 4 rectangular blocks: s-block to the left, pblock to the right, d-block in the middle & fblock below
• The table incorporates “recurring trends”, like similar properties • Table can also predict properties of new elements • Atomic number is # of protons in the nucleusequal to # of electrons • A new row (period) is created when the atom has a new electron shell & has its first electron
• Elements with the same # of electrons in a particular shell occupy the same column • Elements with similar properties belong to the same group • Today, 114 confirmed elements • Only 98 elements occur naturally • There are 18 columns or groups
Can change one element to the next • With a higher atomic number • Simply by giving it energy • If unstable, it will give off this extra energy – doing some useful work – and change back to its original • Example from “Jerusalem Dome of the Rock UFO” • Flash is when it changes into a higher element, then gives off its energy by climbing up fast while it changes back to its earlier form – the element created is probably element 116 which is unstable
Electronic equipment we use • • • •
Necessary to have good conductors (metals) Need special properties of conductors Many of these are provided by the REEs Rare Earth Elements: China has the bulk of them, but others may have them too • Need exploration to find them
Where to find information • Textbooks • Unfortunately, the textbook for this course is out of print, new one not ready
Info on the web • • • • •
Mineral Resource Classification: Wikipedia Ore Genesis : Wikipedia Hydrothermal circulation: Wikipedia Hydrothermal synthesis: Wikipedia Volcanogenic massive sulfide ore deposit: Wikipedia • Seafloor massive sulfide deposits: Wikipedia
Info on elements for project • Look under name of element / metal • Look under deposit of that element / metal • Find something you like or you want to know more about (such as the gems of Manitoba!) • Make a presentation and/or send by email
Where the metals come from? • Every rock you pick has traces of metals, but you can’t see them – in trace amounts • These metals can be absorbed by hot water solutions going through the rocks • The solutions will also have other solvents like sulfur that can dissolve other metals • When conditions change along the way the metals can be deposited – they precipitate out
Examples of changing conditions • Change in temp. or pressure • Change in rock type
Metals • Their abundance in rocks of various types has been measured • In order for them to become “ore” nature has to collect them in some place or trap • This concentration over millions of years of time has created ore deposits • The concentration factors of metals varies quite a lot
Concentration of metals into ore • • • • • • •
Al Fe Cu Zn Au Pt
abundance 8.2% 5.6 % 55 ppm 70 ppm 4 ppb 5 ppb
concentration factor 4 9 180 700 1250 1000
Magma • Dissolves surrounding rocks • Within a liquid mass, some metals can accumulate if they are heavier, for example • These “heavies” accumulate at the bottom of magma chamber and can solidify to form a layered deposit when magma cools down, for example, chromium, platinum
Human history and resources • • • • •
Stone Age Copper Age – but Cu is soft Bronze Age 3,000 BC – Cu + Sn (tin) Iron Age 1,200 BC Many new discoveries since industrialization ~ 200 years ago
Mineral Resources • Resources (available if feasible) v. reserves (ready to mine) • Material of economic interest. Needs to be calculated, usually after drilling. Then, called “ore” • Theories on how materials form in the Earth’s crust: “ore genesis” • Material has a source, usually magma, then it is transported and deposited in a suitable environment (trap)
Ore genesis processes • Inside the Earth: magmatic, hydrothermal, metamorphic • On the surface of the Earth (example, gold nuggets in a river)
Concentration of metals • One can get a clue of the mineralizing solutions from the so-called “fluid inclusions” or remains of those fluids trapped in the rocks
Fluid Inclusions • • • • •
4 common types Aqueous: liquid + minor vapor Aqueous: vapor + minor liquid Aqueous; liquid, vapor, halite, anhydrite CO2 – bearing
Compare them to our own blood • Which passes through our body bringing nourishment, oxygen, etc & removing other substances • (blood is a solution identical to the sea water)
• Most metal deposits are sulfides • But metal sulfides are extremely insoluble in pure hot water • Evidence comes from fluid inclusions: small samples of fluid trapped in minerals • Inclusions contain a lot of Na, Ca, Mg, Cl & S and metals • Metals transported as soluble compounds, such as PbCl2 + H2S = PbS + 2HCl
example • Galena (PbS) precipitated when the lead compound comes in contact with hydrogen sulfide gas
Standard classification of metals
Common ores • • • • • • •
Iron Lead-zinc-silver Gold Platinum Nickel Copper Uranium
• • • • • • •
Titanium and zirconium Tin, tungsten and molybdenum Rare earths, niobium, tantalum, lithium Phosphate Vanadium Gems Industrial minerals (sand, gravel, diatomaceous earth, silica sand)
Iron (Fe) • Mostly magnetite in ancient sediments accumulated on the ocean floor in an oxygen poor atmosphere and acidic water • Weathering converts magnetite into hematite, much easier to process • Some deposits within the Pilbara region of W. Australia formed as placer deposits • They formed by accumulation of hematite gravels called pisolites, which form channel-iron deposits
Iron Formations • Found in Proterozoic rocks (Precambrian) worldwide • Large deposits in Ontario & Quebec • Small occurrences throughout Manitoba – example, near Bissett • Big production in Michigan (cell phones may not work in some places due to abundant magnetite deposits)
Lead-Zinc -Silver • Form by the discharge of deep sedimentary brine onto the sea floor (SEDEX), or by replacement of limestone, some associated with volcanoes. • Vast majority of SEDEX deposits are of Proterozoic age, some are of Jurassic age. • The carbonate replacement type deposits form by degradation of limestone by hydrocarbons which are thought to be important for transporting lead
Pb-Zn-Ag • The minerals are galena & sphalerite. Silver is found in inclusions within galena • Silver-rich galena will have a striped appearance (see hand samples)
Gold (Au) • • • • •
Form in a very wide variety Primary or placer or residual Plate tectonics generates gold deposits Primary are lode or intrusion-related Lodes associated with orogeny or other collision events • Most lode deposits sourced from metamorphic rocks
• Form by dehydration of basalt during metamorphism • Gold transported up faults by hydrothermal waters and deposited when the water cools too much to retain gold in solution • Lode deposits are high-grade, thin, vein or faulthosted. Usually in quartz veins or reefs • Usually hosted in basalt or in sediments known as turbidites, although when in faults that may be in granite
• Intrusive-related gold hosted in granite, porphyry or dikes. May also contain copper, tin, tungsten, etc • These deposits rely on gold existing in the fluids associated with the magma • Placer deposits form via gravity with gold sinking into a trap or bends in rivers
Gold “Reef”, Quebec
East Malartic mine, Quebec
Next to the town of Malartic
Gold in a chert horizon
Laterite gold • Form after prolonged weathering of primary gold deposits • Example: Ketza deposit in the Yukon – see samples
Ketza river mine
Uses of Au • For 70 years it was a standard treatment for rheumatoid arthritis to inject a liquid suspension of gold, which acts like an antiinflammatory – no one knows why or how • Windows coated with Au to help reflect the sun in the summer and retain heat in winter • About 20 % of decorative gold is in the thread of Indian saris
Toronto’s Royal Bank Plaza • • • •
Two 41-and- 26 storey towers Has 14,000 windows All have very thin coating of 24-carat gold leaf 2,500 ounces (70.8 kg) of gold worth over 1 million $
Can you change metal into Au? • Soviet nuclear reactors transformed some lead nuclei into gold
220 oz X $1,500= $330,000
Gold in history • World production from ancient times to now is about 165,000 tons • A lot is reused • Biggest source of gold is in the ocean water, but you can’t recover it • Alexander inherited 5,000 tons of gold –the bulk of the gold produced prior to zero year when he conquered Persia (it brought its gold from Uzbekistan / Tajikistan, Persia had none)
• Egypt has many gold treasures, but the country has no gold – it brought it from Sudan • The Incas of ancient Peru had lots of gold from the volcanic / igneous rocks of the Andes • California “started” with the Gold Rush, later a “Yukon Rush” in the Klondike area (depicted in movies of Charlie Chaplin) • Latest production comes from the shallow “black smokers” of the Pacific ocean
Platinum (Pt) • Pt and palladium are generally found within ultramafic rocks • Source of the metals is rocks that have enough sulfur to form a sulfide mineral while the magma is still liquid • The sulfide mineral (pyrite, etc) gains platinum by mixing with the bulk of the magma because Pt is chalcophile (it likes Cu) and is concentrated in sulfides
• Sulfide phases only form in ultramafic magmas when the magma reaches sulfur saturation. • To achieve sulfur saturation magma must get contaminated with sulfur-rich wallrock or mixed with other magma • Often, Pt is associated with Ni, Cu, Cr and Co deposits
Most of world’s production • Comes from the Merensky Reef in South Africa, a continuous layer that formed by fractional crystallization within one magma chamber • Minor production comes from Thompson, Man. and Norilsk, Siberia • Pt used in seat belts – excellent conductor
Nickel (Ni) • Two types, as sulfide or laterite • Sulfide form the same way as Pt deposits • Ni is a chalcophile element which prefers sulfides, so an ultramafic or mafic rock which has a sulfide phase in the magma may form nickel sulfides. • Best Ni deposits accumulate at the base of komatiite lavas (Mg-rich)
Thompson / Voisey Bay deposits • Subvolcanic sills host Ni sulfide deposits formed by deposition of sulfides near the feeder vent. Sulfide was accumulated near the vent due to the less of magma velocity at the vent interface
Sudbury deposits • The Sudbury Basin or the Sudbury Nickel Irruptive is a major geologic structure in Ontario • It is the second largest impact crater on Earth as well as one of the oldest (1.8 b.y. old) • The large impact crater filled with magma rich in Ni, Cu, Pt, Pd, Au & other metals
Norilsk deposits, Siberia • Largest Ni-Cu-Pd deposits in the world • Deposit formed 250 m.y. ago during the eruption of the Siberian Trap Igneous Province (STIP). The STIP erupted over I million cubic km of lava, a large portion of it through a series of flat-lying conduits • The ore formed when the erupting magma became saturated in sulfur, forming globules of sulfides. These sulfides were then “washed” by the continuing torrent of erupting magma & upgraded their tenor with Ni, Cu, Pt & Pd
Rich Pt-Cu ore
Ni laterite deposits • Similar to formation of gold laterites except that ultramafic or mafic rocks are required • Very large olivine-bearing ultramafic intrusions
New Caledonia
Uses of Ni • The Loonie: bronze plated on pure Ni (7 g wt) • In CDs, cell phones, batteries, electric shavers, golf clubs, credit cards, etc
Copper (Cu) • Either formed within sedimentary rocks or in igneous rocks • Most major copper deposits within the granitic porphyry copper style • Sedimentary Cu forms in ocean basins. Cu is precipitated by brine from deeply buried sediment (similar to SEDEX zinc)
Uranium (U) • Source is radioactive granites when certain minerals like monazite are leached during hydrothermal activity or by circulation of groundwater • U is brought into solution by acidic conditions & is deposited when this acidity is neutralized • Generally this occurs in carbon-bearing sediments within an unconformity
• U also found in coal and in all granites • Radon gas creates a problem in U mining • 40% of world U in the Olympic Dam deposit in Australia. U in granite & porphyry
Uranium City area, Sask. • Production from 1960’s until 1982 • Newer high grade deposits discovered under the Athabasca sandstone Basin in N. Sask. have huge reserves & tremendous potential • Unconformity with underlying basement is the target wherever graphite sediments are present
Canadian Shield
North American craton
Uranium properties/mines
Geology of the Basin
Unconformity U deposits
Rocks with uranium
Top: “comb quartz crystals bottom: fractured rock with many veins
Titanium & Zirconium (Ti, Zr) • Mostly found as mineral sands • By accumulation of heavy minerals in beaches (like placer) • Titanium as ilmenite, rutile & leucoxene • Zirconium as zircon • Thorium in monazite • All found in granite. After erosion & transportation by rivers into beaches
Zircon • Yellow grains in granite • Contains U, Th • Used as a opacifier (make things opaque) in ceramics
Tin, tungsten & Molybdenum • Form in certain type of granites • Skarn deposits form by reaction of mineralized fluids with the rocks – such as limestone surrounding the granite
Tin • To make tin cans • Making bronze • Now only produced in Malaysia from alluvial deposits
Tin veins in granite, Cornwall, UK: details later on
Tungsten • Heavy metal, rare in nature • Used in steel, carbide, lamp filaments
Molybdenum • Found with Cu in porphyry deposits • Used in making steel
Rare Earths, Niobium, Tantalum, Lithium • The majority of REEs +tantalum & lithiumfound within pegmatite • Probable origin by metamorphism & igneous activity • Lithium as spodumene & lepidolite • Carbonatite intrusions an important source of these elements
Bernic Lake, Manitoba: Tanco mine • • • • •
Lithium Cesium (80% of world’s production) Tantalum Columbium Beryllium
Hoidas Lake, N. Sask. • 50 km north of Uranium City • Most advanced REEs property in Canada (ready for mining) • Named after a WWII pilot who died in action • Contains a significant amount of heavy REEs, such as dysprosium- used in hybrid car components • Unfortunately, there is some U in the ore
Phosphate • Used as fertilizers • Immense quantities in sedimentary rocks from the Proterozoic age to now • The source of P is the skeletons of marine animals • Another source is intrusions like nepheline syenite & carbonatites • The P is in apatite & monazite
Vanadium (V) • Found in blood cells of vanabins in the sea • Biological processes responsible for the deposits • Also found in crude oil & oil sands • Added to iron to make steel
Tellurium (means from the earth) has accomplished: • Cheaper photovoltaics • More robust CDs • Spectacular pictures from the Hubble telescope • However, when you work with the metal it enters body and for many months your sweat, urine has a garlic smell!
Classification of deposit types
ORE DEPOSIT MODELS • 14 types
1.Layered mafic-ultramafic intrusions • Intrusions with Ni-Cu sulfides at the base • Fractional crystallization with density stratification • Chromite-rich layers (Cr) – Bird River, Man. • Other metals: Pt group elements • Cross Lake: magnetite with Ti
2.Carbonatite Alkaline intrusions: REEs • Igneous intrusions made up of calcitedolomite-ankerite with apatite & magnetite • Alkaline (Na and K rich) volcanic rocks • Related to continental rifting & alkaline volcanism • REEs: Ce, Y, La, Sm, Eu
Example from Montreal area
“mounts” with various rock types
Mont St. Hilaire, Que. • One of the Monteregian hills • Has 3 distinct intrusions: gabbro, nepheline syenite with pegmatites • Famous mineral locality- rare & exotic • 366 minerals, 50 of which are “endemic” (type location) • Most Fe-rich biotite in the world
Hill with spa
Carletonite : type locality
Rare Earth minerals
Purple syenite complex
“Mounts” around Montreal
Lac St. Jean area: Niobec mine
Syenite pegmatite
3. Porphyry Copper intrusions • Porphyritic granitic rocks with a network of chalcopyrite veins • At collision of plate boundaries of Andean type or island arcs – mountains today • Alteration zones with inner potassic, outer sericite & peripheral chlorite-epidote • Fluids from the pluton followed by later lower temp. fluids leaching Cu & S from the magma & surrounding rocks
Porphyry copper deposits
Cross section
Alteration zones
Example: Cerro Colorado, Panama
The deposit is the whole mountain
Paths are for exploring & moving drill
Platforms are for drilling
Steep terrain
Paths 100 m apart vertically
Camp in the valley
Old volcano in the distance
Geologist
House of natives, this guy had 9 daughters
Armed forces paid a visit
Office and core shack
My map: red is porphyry, green is granite
3D of deposit
Cerro Colorado Cu-Mo deposit • Cu –Mo not visible on surface, they have been oxidized and removed from near surface • The “country rock” is basalt that deposited on the ocean floor • Two main intrusions: a porphyry (red on map) and granite (green). Both are mineralized with a network of veins carrying chalcopyrite (yellow) and molybdenite (bluish) and minor pyrite
Alteration zones • The distribution of the Cu-Mo follows the alteration pattern • Higher grades are in the potassic & sericite zones and lower grades in the chlorite/calcite/epidote zone • There seem to be two separate deposits that formed by the two different intrusions of the area (porphyry & granite) • One of the biggest in the world with reserves over 3 b.tons (reserves calculated down to sea level). Highest elevation is 1,600 m
Made headlines in Northern Miner
2 of the geologists & the boss in NFLD
The deposit does not reach surface
Protests are numerous
4. Complex Pegmatites • Late stage of granitic intrusions that have undergone fractional crystallization • The last fraction of the magma would be rich in water & incompatible elements that could not fit into the earlier formed minerals • Li, Be,B,F, Rb, Cs, REE, Th, U, Ti, Zr, Hf, Sn,Nb
5. Massive sulfides – Cyprus type • Massive pyrite with Cu & Zn sulfides in pillow basalt (ophiolite) • The ophiolite represent portions of the ocean crust formed at mid-ocean ridges. Seawater circulates through fractured basalt & heated to 400’ C, while metals are leached from basalt and deposited on ocean floor • Part of ocean floor is preserved by thrusting onto adjacent continent
Cyprus: origin of the word “copper”
6. Cu-Zn felsic volcanic deposits • Cu & Zn in marine volcanic rocks • In island arcs related to subduction zones • Examples in Japan, Ontario, Quebec
7. Uranium clastic sedimentary deposits • In permeable sandstone that cemented later • U from volcanoes
8. Mississippi Valley carbonate Pb-Zn • Galena, sphalerite, chalcopyrite in porous rocks related to reefs • In dolomite & breccias • Epigenetic ore (after the rock formed) • Cambrian to Carboniferous • Metals from basement. Low-temperature fluids & highly saline with sulfur
Example: Pine Point, NWT
Open pit operation
Pine Point deposits
Galena
Samples showing • • • •
Galena – sphalerite with calcite/dolomite Pockets of sulfur Pockets of bitumen The host rock -limestone/dolomite- has been altered by the mineralizing fluids • When you hit the rock with the hammer it smells gasoline (it contains petroleum/oil from remains of marine animals like corals)
9. Banded Iron Formations • • • • •
Layered with chert Great lateral extent Deposited in shallow water (shelf) Mostly Proterozoic in age High dissolved content of SiO2 and Fe+2 in seawater from leaching sea volcanoes
10. Aluminum Ore- bauxite • Weathering over any aluminum-rich rock (granite) • Mainly Cenozoic • Clay minerals associated with hematite, limonite • Tropical climate promotes breakdown of feldspars into clays rich in Al. Silica, Iron & other solubles leached out • ALCAN: Canadian co. has smelter in Kitimat, BC
bauxite
bauxite
11. Placer deposits: Au, Diamonds & heavy minerals • Pt, Au, diamonds, magnetite, chromite, ilmenite, cassiterite, zircon • Concentration in low-energy areas of stream flow (inner curves of meanders)
World’s largest nugget
12. Tin vein –Cornwall type • Quartz-cassiterite (+/- Tungsten, base metals) veins associated with granite • Intrusions in fold belts or collision of continents • Similarities with porphyry coppers with alteration patterns • Oxides within granite and outer sulfides of Cu, Zn, Pb, antimony
Cornwall, U.K. • Southwest corner of England • People are Celts that have worked the tin mines for ~ 2,500 years • Production from here responsible for Bronze Age • Ancient Greek mariners called the British Isles “the Cassiterides” which means the Tin Islands • In the 1800’s more than 300 mines, declined slowly, none left today
• The miners moved to California, S.Africa & Australia. Some into Ireland where they call them “Tinkers” prob. because they worked with tin. The Irish don’t like them, treat them like the gypsies. Their graves are spectacular & spend a fortune on them – see pictures • The Cornish recently became semi-independent and have their own language (Kernow) • Local products: Cornish pasties, clotted cream
Tinkers’ graves
Granite (red), killas (brown), veins (yellow)
Cornish words • Killas is their word for “country rocks” or local rocks • Elvans is how they call the dikes or small intrusions like walls • Mine names usually start with “Wheal”, like Wheal Jane is one of them
Tin ore
Tin veins
13. Mercury – Almaden type (Spain) • Stratabound disseminated cinnabar (HgS) & native mercury in volcaniclastic sedimentary rock • Permeable sedimentary rocks near volcanic center with faulting • No metamorphism or granite intrusion • Modern hot springs are associated with Hg deposits suggesting ancient deposits formed by circulating hot fluids along faults, with the volcanic rocks acting as the source of the Hg
• Low solubility of Hg compounds requires very large amounts of fluid. Hot springs may provide such an environment • Hg has a low boiling point, it may be transported as a vapor & deposited as pure (native) Hg
Mercury (quicksilver) ore
14. Nickel laterite deposits • Deep weathering of ultramafic rocks in warm humid climate • Enriched in Ni, Co, Cr • Alteration from top down, red & yellow soil (limonite), saprolite, altered ultramafic rocks
Another classification
Abundant Metals • • • •
Al Fe Mg Ti
Scarce Metals • • • • •
Base metals: Zn, Cu, Pb, Sn, Cd, Hg Ferroalloys : V, Cr, Ni, Co, Mo, W, Mn Precious metals: Au, Ag Platinum group metals: Pt, Pd Rare Earth metals
Lightest & Heaviest • Lithium v. Uranium
Non-metals & Industrial minerals • Limestone, clays, sand, gravel, diatomite, silica, barite, gypsum, talc, perlite, zeolites, etc • Used in construction, ceramics, paints, electronics, filtration, plastics, glass, detergents, paper, agriculture, etc
Fertilizers • • • •
Nitrogen Phosphorus Potassium Sulfur
Evaporites • • • • •
Potash Salt (halite) Gypsum & Anhydrite Borates Sodium sulfate
Potash • • • • •
~ 30 % of world’s supply from Sask. Reserves for centuries One danger: flooding by water 1 km deep layers within sedimentary rocks Devonian age deposited in a cut-off portion of the ocean
Salt (halite) • Groundwater down to about a 200 m depth is fresh • Below that it is saline (brine) • An anomaly (man-made or not) can bring saline water higher up – like south of Winnipeg
Salt in Manitoba
Salts in the Prairies
Gypsum • Making gyprock (drywall, plasterboard) • Raw gypsum is heated and water driven off, then partially re-hydrated, wet product then sandwiched between two heavy sheets of paper and dried
Barite (means “heavy”) & usage • • • • •
Has a SG of 4.5 (~ double of ordinary rock) In drilling muds In pigments, paper industry In playing cards (denser) – easier to “deal” Blocks X rays & gamma rays
Silica sand (mostly quartz) • Many, many uses • Found in deposits of sand in non-tropical areas • Making glass, concrete, sandblasting, industrial casting, etc • Fine quartz, however, is dangerous if inhaled (silicosis)
Silicon Valley, California • South part of San Fransisco • Silicon chip semiconductor used in high technology operations (computers) • 1/3 of venture capital in the USA raised here • Best place for high tech jobs in the USA • Many universities • Specialists recruited/come from around the world
The many uses of Fluorite • • • •
Making glasses, enamel & ceramics Non-stick Teflon cookware In production of steel as flux –removes sulfur Has exceptional optical clarity & used as lenses that show extremely sharp image- for cameras, microscopes & telescopes
Sulfur • • • • • •
Bright yellow crystals at room temperature Can react as either an oxidant or reducing Common as sulfide of metals or sulphate Brimstone (burn stone) used as fumigant Rotten egg smell (hydrogen sulfide & SO2) Responsible for smell in cabbage, broccoli, garlic, onion & skunk • In proteins, aminoacids • In Canada, byproduct of natural gas, petroleum & Tar Sands
Carbon • • • • •
All Life is carbon based (organic chemistry) Element known since ancient times Diamond & graphite (good conductor) Found in limestone, CO2 gas & methane CH3 Forms more compounds than any other element, more than 10 million • Has no melting point, it sublimes • Forms carbides (extremely hard) with tungsten
• In order to form Life, carbon needs to get scattered in space as dust from supernova explosions and then later incorporated into a 2nd or 3rd generation star (our Solar System is 3rd)
Graphite • Both USA & EU declared graphite as a strategic mineral • Important in high technology & green energy • 80% produced in China, however, reserves are declining
Many uses • • • • •
Refractories Batteries Brake linings Steel making Laptop computers
Manganese • World’s healthiest foods rich in Mn (cloves, oats, rye, spinach, etc) • We need small amounts in diet • Primary use in making steel • Not found in native (pure) state, usually associated with iron • Name from Magnesia, Greece, confused with magnetite, but Mn NOT magnetic
• Found on the ocean floor as nodules, but too difficult to mine, est. 500 billion tons • Can have neurological problems if too much in the body from drinking water, etc • Used as additive to gasoline (instead of lead)
Selenium (=moon) • Found with sulfur • Used in electronics, glassmaking & pigments • Used in medical pills (thyroid problems) & infant formula • Many thyroid problems in Europe after the Yugoslavia war of 2001 when U bombs were used for first time
Neon • One of the noble gases • Inert, not reactive gas • 5th most abundant element in the Universe after H, He, C, O • Has a notably bright red light • Used in advertizing signs
Aggregates • Sand & gravel • Crushed stone • Cement
Dimension stone • • • •
Limestone – common in Manitoba Granite – expensive, mostly as counter top Gneiss – expensive, mostly as counter top Peridotite – green with marble-like finish, Winnipeg Convention Center • Granite porphyry – Regina Government buildings
Limestone / dolomite/cement
Quicklime or calcium oxide (CaO) • Calcium oxide is obtained by heating limestone at more than 825 degrees C to liberate carbon dioxide gas • If left alone it can grab CO2 from the air to form limestone again • If quicklime is heated to 2,400’C it emits an intense glow, called limelight; was used in old theatres before the advent of electricity • Quicklime is the main ingredient to make cement
(Portland) cement • Bricklayer Joseph Aspdin of Leeds, England first made cement early in 19th cent. by burning powdered limestone and clay in his kitchen stove • To make cement today we use limestone, clay, silica sand and iron ore. They are heated at high temp. and form a rock-like substance that is ground into the extremely fine powder we call cement
cement • Cement is mixed with water to make mortar • Or mixed with sand, gravel and water to make concrete
Other uses of CaO some info from visit to Limestone Quarry
• To neutralize acidity in base metal mines, like in Flin Flon who are treating sulfide-rich ore (acidic) • With water it gives out a lot of energy, so it can be used for on-the-spot food warming • Farming to neutralize acidity in soil • In pulp mills • In petroleum industry
Rock/Mineral collecting in Canada • 130 clubs • Bancroft, Ontario: 1 of only 3 in the world, where ancient conditions created nearly every known volcanic & metamorphic rock & mineral • Mont-St-Hilaire, E of Montreal – among the top 10 in the world sporting 366 minerals
• Bay of Fundy: endless varieties of agate also zeolite & amethyst • Thunder Bay: abundant amethyst, even the highways are purple in color. Also agate • Souris pit: agates & petrified wood
Bancroft, Ont. • Major attraction is the mineral-rich pegmatites. They are like magma that could not come to the surface as lava, instead it cooled at depth slowly • Rose quartz (color due to Al?) is prominent • Apatite, sodalite, rare earths, uraninite, zircon • Marble was used across the country
Feldspars, a major product • • • •
Part of ceramics, enamel, pottery To make paints, soaps, roofing, tiles Its highest grade to make false teeth Its lowest grade in whipping up stucco
The elements in FIREWORKS • Ancient Chinese used a mixture of sulfur, saltpeter and charcoal that was very flammable and would explode if put in a miniature amount of space. That was 7th cent. • However, at the same time the “Greek Fire” was invented in 672 AD. Although its composition was a state secret and remained so, it must have been a mixture of things like pine resin, naphtha, quicklime, sulfur & niter
The “Greek Fire” – in Greek, “liquid fire”
Clay grenades filled with Greek Fire
Anatomy of fireworks: many parts • A launching tube, 3 X the length of the fireworks shells, but exactly the same diameter • When the gunpowder ( 75% saltpeter, 15% charcoal, 10 % sulfur) burns, the heat and gas are trapped & force their way to the surface until an explosion happens & they become airborne • A fuse
Ingredients • An oxidizer, a reducing agent, a coloring agent, binders and regulators • Oxidizers (chlorate) produce the oxygen to burn the mixture • Reducing agents burn the oxygen to make hot gases • Binders hold the mixture in a lump
Incandescence & luminescence • The light produced from heat is incandescence • Ti & Al used to increase the temp. & cause the firework to burn brighter • Light produced by energy sources other than heat is luminescence • Energy absorbed by an electron will cause it to be excited. When the electron’s energy is lowered it is released as light
Colors • • • •
Cu creates blue Al to give silver & white colors & sparks Zn makes smoke clouds Ba for green, Sr, Li for red, Mg for white, Na for gold & yellow • Cl brightens the colors
Fluorescent Minerals • UV radiation generated by a uv lamp • About 15% of minerals respond well to longwave uv energy • Named after fluorite, the 1st mineral to show it • Longwave LED (Light-emitting Diode) lights are popular, they generate less heat than ordinary ones • You can’t look directly into uv light, it’s like looking at the sun • Also uv light burns the skin
Fluorescent minerals
GEMS & gemstones • Have intrigued people for the last 7,000 years • The first known were amethyst, rock crystal, amber, garnet, jade, jasper, coral, lapis lazuli, pearl, serpentine, emerald and turquoise • Were reserved for the wealthy as status symbols. Sealed documents had jewel-encrusted seals • Had a mystery, spiritual & were worn as amulets. They could repulse evil, preserve health
Warning! • Imitations of gems with synthetic varieties are widespread today • You can easily be fooled by merchants
• Up to the beginning of 19th cent. used as medicine against illnesses • Even today calcium tablets made out of powdered pearls are sold for medicinal purposes in Japan • Linked to astrology and allocated to zodiac as birthstones • Priests, bishops and kings wear them
Austrian crown recovered in Winnipeg in 2007! • A strange bank robbery on Empress St. in 1998 surprised police who conducted a world-wide search that ended in a St. James home where the Austrian jewel-encrusted broach – the Koechert Pearl Diamond of the Empress of Austria- was found. It had been stolen 9 years before • A very sophisticated robbery
Precious & semi-precious stones • • • • •
In the past were only a few, now many Most are minerals No official list Semi-precious are softer stones Profusion of names, some created to boost sales, examples are tanzanite (blue zoisite) and tsavorite (green garnet)
Physical properties • Crystal structure • Crystals grow in the available open spaces in the rocks, so they take up various shapes • Hardness: most gems are hard • Specific gravity • Color (can be modified or changed) • Refractive index & double refraction • Inclusions (old “flaws”)- may boost price • Mining still primitive (except for diamonds)
Gem deposits • Rare, because the conditions that promote their formations are unusual and thus worthy of scientific study • Basically, if you want to prospect for gems go to the mountains or eroded mountains, like in Manitoba
GEM deposits • Can be classified according to environment of formation or present location • 1. Magmatic • 2. Hydrothermal • 3. Metamorphic • 4. Sedimentary • 5. Placer Some can be found in more than one class
1. Magmatic • Diamonds found within volcanic kimberlite – names from Kimberley, S. Africa- and lamproite – Argyle mine in W. Australia • Vertical pipe-like bodies called diatremes • Kimberlite forms from a very explosive volatile-rich (high pressure) magma that forms ~ 150 km below the surface. As it travels upwards it fractures surrounding rocks, so kimberlite has many xenoliths (foreign rocks)
Canada’s 1st mine at Ekati, NWT opened 1998 Currently, world’s 3rd biggest producer: Canada Arkansas has a “diamond park” open to the public (finders-keepers). The eroded surface of an ancient volcanic pipe, 95 m.y. old
• Biggest ever found: Cullinan at 3106 carats, the “Star of Africa” – polished 530 carats • 2nd biggest from same mine, Cullinan II, at 545 carats- polished 317 carats • Largest diamond in Canada came from the Attawapiskat mine at 35 carats • Canadian diamonds are also called “conflictfree”, but don’t tell that to the Attawapiskatees
Attawapiskat
The rough Cullinan
Sapphires (name means “blue stone” originally used for lapis)
• Yellow/green/pink/blue varieties of corundum • Formed deep inside the crust & were brought in basaltic magma. However, they are rare • Economic deposits only found when basalt is weathered & eroded away, leaving behind the heavier minerals such as sapphires & zircons which become concentrated in placer deposits
Corundum Al2O3 • Sapphire and Ruby • Second hardest mineral / substance • Synthetic corundum used in optical scanning devises like grocery store checkout counters • Originate in marble / gem gravel deposits • Source thought to be basalt • Ruby can have unique asterism aspect
Madagascar • One of the poorest countries in the world • > 50 % of population below poverty line of $1/day (World Bank) • Has one of the largest gem deposits on the planet • The sapphire trade links some of the poorest people to some of the world’s richest people • Temporary communities hunt along rivers & keep moving
Canada’s 1st sapphire • On Baffin Island, Nunavut • Sampled in 2004 yielded 142 grams • One stone (picture) produced a 1.17 carat sapphire gem – the first in Canada
Ruby • Can also be classified under metamorphic or placer
Ruby
Other magmatic • • • • •
Peridot: olivine found in mantle xenoliths Labradorite: in basalt Zircon: in granite/basalt/carbonatite Apatite: in carbonatites Garnets: in basalt /granite/gneiss
Peridot (olivine)
• • • • •
Found in lavas and rocks from the mantle Can be mistaken for an emerald Can also be found in meteorites (pallasites) Largest gem is 310 carats A 3 to 4 carat stone sells for $ 40 – 80
Labradorite
From Madagascar
• Type location is in Paul’s island, Labrador, but also found in other places • Found in basalt and gabbro • Iridescence produced within crystals of feldspar by light diffraction between “layers” • A pendant, 26 X 40 mm sells for $35
Zircon
Apatite
2. Hydrothermal deposits • Most gemstones formed from volatile-rich fluids in pegmatites • Opal, turquoise • Li & B –rich form tourmaline • F-rich form topaz • Be-rich form beryl or aquamarine • Emerald, also from Be-rich fluids
• Volcanic opal also from fluids. It contains many inclusions of water & cracks easily • Ancient mines in Slovakia worked for 2,500 years. Found in Nevada, Mexico & Australia • Amethyst, agates, petrified wood & chalcedony are all varieties of quartz or silica & form from hydrothermal fluids in volcanic environments
Turquoise (means “brought through Turkey”) • Derived from low temp. fluids by the weathering of pre-existing sedimentary phosphate deposits • Mined for 4,000 years • Found in Persia (Iran, country of the “pure”race), Arizona, Mexico • Beware of imitations! • $ 2 to $40 per carat
Turquoise
Aztec God of Fire
Dome of the Rock, Jerusalem
PEGMATITES • The source of the world’s finest tourmaline, beryl & topaz and the main source of more than 70 gemstones • Host to an extreme diverse mixture of exotic minerals & the sole source of very rare minerals • Combination of gigantic crystals & extreme enrichment of rare elements
Baffin Island, Nunavut: white lines are pegmatites
Aquamarine
• Important source of Be, Nb, Ta, Sn, Li, Rb, Cs & Ga • Most of the world’s renowned pegmatites are now mined mainly for gems • Pegmatites come in many sizes & shapes • Their internal structure can be simple (all crystals same size), zoned (layers of many sizes of crystals), while the complex have superimposed areas of later alteration with other minerals
• Complex pegmatites have pockets or vugs lined with beautiful gem crystals • The main ingredients of most pegmatites are quartz, feldspar and mica • Gems may form layers in between the above or as pockets
Fluids rich in • H2O, B, Li, F, P, CO2 • Rare elements such as Cs, Ta, Nb, REE, Zr, U, Sn
“Gem pockets”
Colorado
Tourmaline • • • •
Great variety of colors and compositions A boron silicate with many other metals Found worldwide A large cut gem of 191 carats, flawless oval from Brazil was presented in Montreal in 2009 for selling purposes • Another from Mozambique sells for $ 5,000 per carat
This picture can’t be copied!
Topaz
Topaz • A silicate with aluminum and fluorine • Name from name of a small island in the Red Sea (Topazos) where a yellow stone was mined • It may not be the mineral we call topaz today • Price per carat: from $10 to $700
Colorless variety
Yellow variety
Beryl • Price per carat: $30 to $200 • A beryllium silicate • Name means “precious blue –green color –ofsea-water stone”
Aquamarine: blue variety of beryl • Means “water of the sea” • Color can change or be improved by irradiation
Emerald: green variety of beryl • Symbol of immortality for 4000 years • Cleopatra’s mine was thought to be the only source • Now, it is possible to track gem to it source, country and individual mine! • They have very specific oxygen isotope levels, reflecting composition & temp. of the fluids that deposited them as well as the rocks that its elements flowed through
“The Secret Life of Emeralds” • To measure the isotopes, bombard gem with a beam of charged caesium atoms • Those from the Holy Crown in France came from the Swat-Mingora distruct in Pakistan, a big surprise to the investigators • Another surprise was emeralds in India came from Columbia! • Columbia emeralds are unique, rich in color, clarity and bigger crystals
• Green color due to trace amounts of chromium and some vanadium • Relatively rare stone, hence it is very pricy • Price per carat: from $20 to $500 or much higher • Hardness 7.5 to 8 (one of the hardest substances)
Canada’s emeralds • Yukon: found in pegmatites, are Vanadiumrich, discovered in 1998
Yukon’s emeralds
Dryden, Ont. emeralds
3. Metamorphic deposits • Garnet, lapis, zoisite, ruby & emerald • Most rubies in high-grade meta. rocks like gneiss & marble –Burma the largest producer • Most of world’s emeralds mined in carbonaceous schists in Colombia • Lilac/purple variety of cordierite (iolite) in gneiss (in Manitoba)
Jade (green due to Fe) • • • •
World’s toughest stone Mixture of two minerals: jadeite & nephrite Lillooet area has the world’s biggest reserves Prized for its toughness & its almost mirror finish when polished • When hit with a hammer, it produces tiny, feathery cracks, unique for jade
• Jade is an aggregate of two minerals, jadeite (pyroxene) & nephrite (amphibole) • Very tough, the two minerals are strongly interlocking • Jadeite is glassy, bright & crystalline. Found mostly in Burma • Nephrite is what the Chinese have venerated for millenia. BC has reserves to meet world demand for several hundred years
Unworked
Display at Jade City, BC
Bringing more pieces
In China jade worth more than gold
Prospecting for jade in Jade River, China
Garnet • Six varieties with different names • Differences in chemical composition and color • Used as gemstones and abrasives (sandpaper) since the Bronze Age • Also, sand blasting and wood finishing • Abundant supply in mineral sands in India & Australia
Deep red color
Lapis Lazuli “heaven stone” • Means “stone of the blue” • In ancient times known as “sapphirus”, which today we use for the blue corundum (sapphire) • One mine in Afghanistan, 7,000 years old (Sar-eSang) in the region called Badhakshan (name from ancient Greek Balaskia, which means the Vault). Treacherous terrain of precipitous mountains • Flourishing trade due to its unusual color • Color due to sulfur-rich mineral, also contains grains of pyrite & white marble
4. Sedimentary deposits • The most valuable is precious opal • Some deposits are complete replacement of fossil shells, dinosaurs, belemnites, etc • Others are as replacement layers within sedimentary rocks, but discontinuous & as small pods a few cm thick
Opal, Australia
Coober Pedy, Australia
Opalized bivalve (seashell)
250,000 mine shafts!
“Opal capital of the world”
“dugout”
Coober Pedy • In the middle of the desert • To avoid extreme heat of the summer people dug underground houses. They remain at constant temperature. Cost as much to build as house on surface. You can do mining at the same time • Prospectors given 15.3 m2 parcels of land to explore. No large-scale mining allowed
5. Placer deposits • Because of their toughness and resistance to erosion, gemstones are relatively abundant as placer deposits along rivers • Diamonds, sapphires, zircons, topaz, rubies, garnets, agates & petrified wood
Mineral sands: everyone, every day are using them • Paint on the wall, color in clothing, printing inks, ceramics on the wall, TVs, computers, make-up, medicines, etc • Ilmenite • Zircon • Rutile • monazite
Where? • India, Australia, Brazil • All these minerals are heavier than normal rocks, so they tend to separate • Important source of REEs, Ti, Th, Zr and gems like diamond, sapphire & garnet • Low-grade operations. Only in some countries, there is rehabilitation after mining (Australia, Namibia, Chile)
Ilmenite (TiO2) • Weakly magnetic (contains some Fe) • Difficult to distinguish from magnetite, but it has a white rim of leucoxene • Main source of Ti metal • Main Ti mineral in the Cross Lake deposit • The Vanadium content of the Cross Lake is not good for processing • Its powder is white
Black ilmenite with leucoxene rim
Ilmenite (titanium) • Refined as TiO2 pigment, one of the whitest substances on Earth. The unique reflective and opaque characteristics of Ti dioxide form the basis for most high quality coloring agents, giving paints and dyes a brilliance rarely seen before the 20th century • Titanium is highly resistant to corrosion in sea water and has the highest strength-to-density ratio of all metals
Zircon • Used in ceramics, refractories, chemical processing and insulation, zircon is one of the toughest materials in existence. Improved technology is creating a demand for zircon as a valuable component of futuristic engines, bearings, computer disc drives and cutting equipment • Zircon silicate in composition, but it may contain REEs, U, Th
• To produce zirconium dioxide, one of the most refractory materials known • Zircon’s main use as a opacifier, in ceramics • Due to inertness, durability & hardness, it persists weathering and remains in sands • Valuable mineral for radiometric dating due to small amount of U & Th that it contains
Can’t copy!
Rutile • Rich in titanium dioxide, rutile is the feedstock for the new generation of pollution-free pigment plants. Raw material for light durable titanium metal, rutile is essential to the aerospace industries. Non-reactive Ti is the most successful “human space parts” material for modern surgery • Has special optical properties (very high refractive index), so used in optics • Used as sunscreens to protect against UV
• Composed of TiO2 • Most common natural form of TiO2 • May also contain iron, niobium & tantalum
Monazite (= to be solitary) • Separated into rare earths, monazite provides elements vital to some of the most exciting developments in modern technology. Computers, medical technology and electronic industries are all dependent on rare earths • A source of Thorium • May also contain He- extracted by heating it • Can be radioactive – used for dating rocks
Ce, La, Th, Nd, Y phosphate
Old monazite mine in North Carolina
Videos on gems • 1. “Stones of Seduction”: rubies & sapphires • Color of rubies due to chromium • Color of sapphires due to iron & titanium • “Crown Jewels” in the Tower of London, over 350 years old preserved in very clean air • Found in Sri Lanka in alluvial deposits (rivers)
2. (video) Topaz • • • •
Place for irradiation in Vancouver turns them into blue color yellow “Imperial Topaz” from Brazil is very rare A Gemologist needs to do tests to prove it is: take a picture, weigh & measure it, look under the microscope, use a refractimeter to test its refractive index & its specific gravity • Value at $ 7,700
3.(video)Colombian Emeralds: “value is in the color”
• Formed with pyrite, so they contain no iron. That makes them glow more & fluoresce in the sun • 1,000 year old Muzo mine still using old mining methods with many poor people sifting mud in the river below hoping to get rich • Emerald Trading Centre in Bogota • People buy there & bring to sell in the USA/Canada Up to $ 9,000 per carat
4.(video) Amber • • • •
Poland & Kaliningrad, Russia Amber floats because it is lighter than a rock For jewelry & fossil inclusions Russians also make “pressed amber” by melting small pieces • Many imitations
EXPERIMENT • With samples of sand • Remember: it is the rivers that break down rock to form sand. So, rivers act like the “crushers” of the Limestone plant
Small collection of “sands”: 7 samples • • • • • •
2 from shores of lakes 1 from wind-blown shore of lake 1 from an esker 1 from Michelle’s sand deposit – river/esker? 1 from volcanic island with black sand 1 unknown purple sand (Manitoba)
All tested with a magnet • Magnet will pick magnetite/pyrrhotite, but may also pick ilmenite • The amount of magnetic material will be an indication of how much “mineral sands” we may have in the samples
Results • • • • • •
2 shores of lake: NONE 1 wind-blown from shore: NONE 1 esker : some 1 Michelle’s : some 1 volcanic island: a great deal 1 unknown: lots
Conclusion • Lake shore sand may have been separated, with “heavies” underneath the “lights” • Esker and river sand may be sources of “mineral sands” • Anyone dredging a river bed – to avoid/reduce risk from flooding – can pick up some credits
Other gems in Canada • • • • • • • • •
Sapphire Ruby Beryl: emerald & aquamarine Topaz Tourmaline Spinel Cordierite Zircon Peridot
• • • • •
Garnet – almandine Garnet – pyrope Garnet – spessartine Quartz – amethyst Quartz - citrine
Corundum • • • •
Nunavut Ontario BC Newfoundland
Beryl (emerald) • • • •
Ontario: Dryden area NWT Yukon Nunavut
Beryl (Aquamarine) • • • • •
BC Yukon Ontario Quebec Nova Scotia
Topaz • BC • Yukon
Tourmaline • • • •
NWT Quebec Nunavut Ontario
Spinel • Ontario • Nunavut
Cordierite (Iolite) • • • • •
BC Ontario Manitoba NWT Nunavut
Cordierite • Northern Manitoba: blue-violet with strong pleochroism • Many applications as insulator, resistor, etc
Zircon • Ontario
Peridot • • • •
BC Yukon NWT Ontario
Garnet: many kinds • • • • • •
Ontario Quebec NWT Yukon Nunavut BC
Manitoba minerals • Staurolite (cross-shaped) • Cordierite • Gypsum rosettes in the soil, esp. in the Floodway • Lepidolite (Li) • Pollucite (Cs)
A trip to the Lapis mines
Balaskia, Afghanistan
Follow the Korcha river
Man wearing “kausia”, ancient Greek hat
Florida restaurant
At the end of the Korcha river
Remains of ancient Greek city, Afghanistan/Tajikistan border, Korcha/ Amur rivers
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