Rocks and Minerals
Composition: Calcium Carbonate
Uses: In cements and mortars, production of lime, limestone is used in the steel industry; glass industry, ornamental stone, chemical and optical uses and as mineral specimens.
Composition: Copper, commonly associated with iron and silver
Uses: Native Copper was the only source of copper until the turn of the century, when extraction methods were improved. The copper ores are far more abundant than Native Copper, and are therefore the main source of copper nowadays. Even though, Native Copper is a sometimes mined as a minor ore of copper. Copper ranks second for as most-used metal in the world. The special properties of conductivity, malleability, resistance, and beauty make it so popular. The main uses of copper are electrical, due to the greatness of copper’s conductivity, which offers the lowest electrical resistance after silver. Copper is very ductile and can be drawn into very thin wires, which serves as its primary electrical function. It is used for electrical machinery such as motors, electromagnets, generators and communication devices.
Copper has been fashioned into ornamental objects and cooking utensils. Coins have been made of copper throughout history.
Copper is also used in pigments, insecticides, and fungicides, although it has of lately been largely replaced by synthetic chemicals.
Composition: Iron chromium oxide, sometimes with some magnesium. Forms a series with the much rarer Magnesiochromite.
Uses: Chromite is the main ore of chromium.