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Ancient Uses of Copper
As in ancient times, copper remains a component of coinage used in many countries, but many new uses have been identified. One of copper’s more recent applications includes its use in frequently touched surfaces (such as brass doorknobs), where copper’s antimicrobial properties reduce the transfer of germs and disease. Semiconductor manufacturers have also begun using…
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How Do We Use Copper Today?
Presently, copper is used in building construction, power generation and transmission, electronic product manufacturing, and the production of industrial machinery and transportation vehicles. Copper wiring and plumbing are integral to the appliances, heating and cooling systems, and telecommunications links used every day in homes and businesses. Copper is an essential component in the motors, wiring,…
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Copper – A Metal Used Through The Ages
Copper was one of the first metals ever extracted and used by humans, and it has made vital contributions to sustaining and improving society since the dawn of civilization. Copper was first used in coins and ornaments starting about 8000 B.C., and at about 5500 B.C., copper tools helped civilization emerge from the Stone Age. The discovery that…
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Other Minerals Can Fool You!
Chalcopyrite and small pieces of biotite or phlogopite mica can fool you. Chalcopyrite (a copper iron sulfide) has very similar properties to pyrite. It has a lower hardness than pyrite (3.5 to 4) and a lower specific gravity than pyrite (4.1 to 4.3), but the same tests can separate chalcopyrite from gold. Chalcopyrite also has a greenish black streak. Pyrrhotite is…
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Destructive Tests
A) Streak: Gold has a yellow streak. Pyrite has a greenish black streak. B) Hardness: Gold has a Mohs hardness of 2.5, while pyrite has a Mohs hardness of 6 to 6.5. Gold will not scratch a copper surface (Mohs hardness of 3), but pyrite will easily scratch copper. Gold can be scratched by a sharp piece of copper, but copper…
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Non-Destructive Tests
A) Tarnish: Most specimens of pyrite, found in nature, will have at least some tarnish on their surface. Nuggets or small flakes of gold are usually bright and untarnished. B) Color: Pyrite has a brassy color. Gold has a golden to yellow color. Most native gold is alloyed with silver, and if the silver content is high enough, the specimen…
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Separating Fool’s Gold from Gold
Here are a few simple tests that almost anyone can use to tell the difference between pyrite and gold. They can usually be done successfully by inexperienced people. However, wise people obtain a couple small pieces of pyrite and a couple small pieces of gold and use them to gain valuable experience. CAUTION: All pieces…
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What Is Fool’s Gold?
“Fool’s gold” is a common nickname for pyrite. Pyrite received that nickname because it is worth virtually nothing, but has an appearance that “fools” people into believing that it is gold. With a little practice, there are many easy tests that anyone can use to quickly tell the difference between pyrite and gold. The nickname “fool’s gold”…
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Imitation Rhodochrosite
Beads and cabochons made of imitation rhodochrosite are in the gem and jewelry market. They are made from powdered mineral matter, in pink and white colors, and bound together with resin. The powders are layered and swirled together to produce a banded appearance similar to much natural rhodochrosite. To the unaided eye, the material looks…
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Rhodochrosite as a Gemstone
Rhodochrosite is a favorite gemstone of many people. It is often slabbed to show off its banded or concentric patterns. Most of the slabs are used to cut cabochons. Cutting rhodochrosite is a difficult job because the material has perfect cleavage, and it is so soft that it can be difficult to polish. Nice, stable, slabbed material is…