Copper Ore There are many types of copper ore, but the most common is the golden-yellow metallic sulphide, chalcopyrite, which is actually a compound of copper, iron, and sulphur (CuFeS2). Pure copper is used extensively in household plumbing and electrical wiring, switches, electric motors, and generators. Mixed with other metals such as zinc, tin or nickel, it produces a range of alloys. Brass, a gold-coloured alloy of copper and zinc, is used for musical instruments, for a variety of decorative household items, and for such things as handles, taps, and picture frames. Cupronickel is an alloy of 75% copper and 25% nickel used to make coinage in some countries. Bronze, an alloy of copper, tin and zinc, is used principally for medals and statues. Less common, but more spectacular, uses for copper include the roofing for important buildings – the Canadian Parliament buildings are roofed with copper sheeting – and for the hulls of wooden sea-going ships to protect them from wood-boring molluscs. Most of Saskatchewan's copper has been mined from copper-zinc deposits that occur in the area between Hanson Lake and Flin Flon, Manitoba. The bulk of copper and zinc production came from the 62 million tonne Flin Flon ore body, two-thirds of which was located in Saskatchewan. This giant deposit was mined between 1930 and 1991.

Copper-Zinc Ore Copper-zinc ore is a mixture of two main minerals: chalcopyrite (a golden-yellow metallic copper-iron sulphide – CuFeS 2) and sphalerite, also known as zinc blende or blackjack (a black metallic zinc sulphide – ZnS). The two minerals are commonly banded together in thin layers giving the ore a striped appearance, and are nearly always accompanied by the iron sulphides pyrite (FeS 2) and pyrrhotite (FeS). Pure copper is used extensively in household plumbing and electrical wiring, switches, electric motors, and generators. Mixed with other metals such as zinc, tin or nickel, it produces a range of alloys. Brass, a gold-coloured alloy of copper and zinc, is used for musical instruments, for a variety of decorative household items, and for such things as handles, taps, and picture frames. Cupronickel is an alloy of 75% copper and 25% nickel used to make coinage in some countries. Bronze, an alloy of copper, tin and zinc, is used principally for medals and statues. Less common, but more spectacular, uses for copper include the roofing for important buildings – the Canadian Parliament buildings are roofed with copper sheeting – and for the hulls of wooden sea-going ships to protect them from wood-boring molluscs. Zinc is used in coinage, as a component of brass, bronze, and die-cast alloys such as those used in cars for door handles and trim, and as the coating on 'galvanized' steel, which is used for everything from fence wire, buckets, air ducts, and bins to car bodies and girders. Zinc compounds are used in medicine (for example, calamine lotion and skin plasters), photocopying, television screens, paints and wood preservers, inks, dyes, oils, fluxes and grease, animal feeds, and fertilizers. Saskatchewan copper-zinc deposits occur in the area between Hanson Lake and Flin Flon, Manitoba. Most of Saskatchewan's copper and zinc production came from the 62 million tonne Flin Flon ore body, two-thirds of which was located in Saskatchewan. This giant deposit was mined between 1930 and 1991.

Diamonds

Photographs of diamonds courtesy of Shore Gold Inc.

Diamond is the denser of the two crystalline forms of pure carbon (the other is graphite), and is renowned for being the hardest naturally occurring mineral. However, despite its hardness, diamond can be 'cleaved' or split along certain crystal structural planes, and this is the basis of the 'cutting' that transforms a rather dull looking crystal into a fiery, sparkling gem. Pure diamond forms perfectly clear and colourless octahedral (double pyramid) crystals that have a slightly greasy appearance. Small amounts of impurities in the crystal lattice may colour the crystals yellow, pink or blue; impurities in the form of larger inclusions decrease the clarity and can cause less desirable darker colours such as brown and black. Most diamonds are found in kimberlite, a volcanic igneous rock that comes from great depths beneath the Earth's crust. Diamond is used both as an industrial mineral and as a gemstone. Industrial diamonds are the small impure crystals used exclusively for their hardness in drills and saws that require extremely sharp, long-lasting abrasive surfaces and cutting edges that will cut through materials such as hard steel, rock, and concrete. The use of diamond as a gemstone depends on its colour, clarity, and "cut-ability"; all of which influence the behaviour of light passing through it. Diamond has a high refractive index and dispersion. This means that rays of light passing through diamond are bent sharply as they enter or leave the gem and are further split into rainbow colours. Diamonds are cut into well-defined shapes in order to fully exploit these properties, so that the gem sparkles and flashes. Diamond discoveries in Saskatchewan were first announced in 1988, during a period of intense exploration across the country that resulted in the discovery and development of Canada's first diamond mine, the Ekati, in the Northwest Territories. Since then, over 70 diamond-bearing kimberlite bodies have been discovered in Saskatchewan, in a large area around Fort à la Corne, northeast of Prince Albert.

Gold Ore In this particular sample of gold ore from the Star Lake Mine, the host mineral is pyrite or fool's gold, the brassy yellow mineral that is set in white quartz. Gold is present in the pyrite as microscopic beads only 4 0 microns (0.04 millimetres) across, and is extracted by crushing and grinding the ore to a powder, dissolving the gold in cyanide, and depositing it on steel wire wool by electrolysis. The final step of the process is melting the steel wool down and extracting the gold when it forms a separate liquid phase from the steel. Ore such as this grades about half a troy ounce per short ton (about 15 grams per tonne) equivalent to something the size of two 25-cent pieces in a cube of rock 75 cm across. Saskatchewan has had a series of small short-lived, but very economical, gold mines develop since the mid-1980s: Star Lake (produced 76,947 ounces, operated 1987 to 1989), Jolu (203,751 ounces, operated 1988 to 1991), Jasper (82,697 ounces, operated 1990 to 1991), Contact Lake (188,210 ounces, operated 1995 to 1998), and Komis (26,885 ounces, operated 1996 to 1997). The only currently operating gold mine is the Seabee Mine, owned by Claude Resources Inc. The company reports cumulative production since opening in December 1991 of over 880,000 ounces of gold, and average historical production of about 47,000 ounces per year. The main use for gold is in jewellery and as a store of wealth in the form of bullion bars and coins. Gold is also used in electrical components (contacts), thermocouples, dentistry, reflective coatings on windows, space suits and satellites, and in decorative gold leaf on ceramics, statues, buildings, glassware, pictures, and books.

Lead Ore The principal ore of lead is the silvery metallic compound of lead and sulphur known as galena (PbS). Galena breaks along three sets of surfaces at right angles to each other to produce stepped box-shaped fragments with mirror-like surfaces, hence the characteristic sparkle of broken ore. Over two-thirds of all the lead produced is used in lead/acid storage batteries (the type used in cars). Elsewhere, lead is used in bearings, balance and counter weights (for example for fishing and in pianos), in construction for flashing, roofing and down pipes, as sheathing for underground cables, in ammunition, and as a protective shield against X-rays and other radiation. Lead compounds are used in corrosion-resistant industrial paints, glass, glazes, TV screens, dyes, adhesives, matches, and rubber substitutes. Because of increasing concern over the toxicity of lead, it is being substituted in many of its former uses and has been replaced in plumbing (with copper), shot (with steel), paint (with zinc), and gasoline additives. The chief impurity in lead is silver, and lead ores are one of the main sources of this metal. Saskatchewan does not currently produce any lead, but over 5.5 million kilograms were produced from the Western Nuclear Mine at Hanson Lake between 1967 and 1969.

Potash Ore Sylvite – Provincial Mineral Emblem of Saskatchewan Potash ore is predominantly a mixture of three minerals: halite (sodium chloride or common salt – NaCl), sylvite (potassium chloride – KCI), and lesser amounts of carnallite (hydrated potassium magnesium chloride – KMgCl3·6H20). Other accessory minerals, such as anhydrite, dolomite, quartz and clays, may also be present. Iron-oxide staining is responsible for the ore’s characteristic pink to reddish-brown colour. Saskatchewan produces about 30% of the world’s potash from 10 potash mines that employ around 4,000 people. Annual average production is over 14 million tonnes of KCl worth over $3.7 billion. Potash deposits form part of the Middle Devonian Prairie Evaporite Formation, a sequence of rocks that was deposited during the evaporation of a large inland sea. The potash horizons underlie the province at depths between 1.0 and 1.5 kilometres, in a broad band stretching between Estevan and Yorkton to Maple Creek and Lloydminster. Reserves are sufficient to last over 600 years at current rates of mining. About 96% of the potash produced is used for agricultural fertilizer; the balance is used in the manufacture of potassium chemicals, ceramics, glassware, soaps, detergents, dyes, colour television tubes, and synthetic rubber. Potash was chosen as the provincial mineral following a province-wide competition open to grade eight students, and was officially announced as the Mineral Emblem of Saskatchewan in February 1996 by the Minister of Energy and Mines.

Salt Common salt or halite (sodium chloride – NaCl), is perhaps the best known of all minerals, being essential for the seasoning and preservation of food. It is the main constituent of the salt in the sea, and is deposited wherever sea water dries up. The Middle Devonian Prairie Evaporite Formation was deposited in just this way during the evaporation of a large inland sea that covered the province some 380 million years ago. The Prairie Evaporite Formation underlies the province at depths between 1.0 and 1.5 kilometres, in a broad band stretching between Estevan, Yorkton, Maple Creek, and Lloydminster. Halite was precipitated together with potash (a mixture of sylvite – KCI and carnallite – hydrated potassium magnesium chloride – KMgCl3·6H2O). In Saskatchewan, salt is recovered by solution mining methods and as a by-product during potash production. Saskatchewan produces about 1.2 million tonnes of salt a year, worth around $27 million. Over half the salt production in the world is used in the manufacture of chloralkali (sodium and chlorine) chemicals, which are themselves used in the production of polymers, paper products, glass, soaps, detergents, and for sewage treatment. Salt is also used extensively in agriculture (salt licks), food preparation, preservation and pickling, water conditioning, drilling muds, as a de-icer on roads and runways, and as a flux in aluminum smelting. The blue colour seen in this specimen of halite is quite rare and is attributed to strain in the crystal lattice. It will disappear if the sample is heated.