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Since ancient times, people have collected things of beauty and value, and have used gemstones to adorn themselves. The appeal of gemstones, their beautiful colors, their rarity and durability have made them precious objects. Throughout history, gemstones have been seen as symbols of wealth and power. Gemstones have also been offered as prestigious gifts.
Gemstones are generally minerals that are used for adornment or for jewelry. To be regarded as a gemstone, a mineral must be beautiful, rare, and durable-hard enough to withstand constant use or handling. There are more than three thousands natural minerals, but less than a hundred are commonly used as gemstones.
Most gemstones are mineral gems, and are found in rocks or in gem gravels. However, a few gems such as amber, pearl, coral, and ivory come from plants or animals. These gems are known as organic gems. Organic gems are not as durable as mineral gems; they are usually polished, carved, or drilled and threaded as beads.
In its natural state, a mineral gem is referred to as rough. Some natural crystals are attractive enough to be displayed as they are. Most are cut or faceted, and polished to show their best beauty. A simple cut for a stone is cabochon, a highly polished domed-shaped top, and a flat or rounded base. Cabochon stones are often seen in antique jewelry. Today most gemstones are cut to give them a number of flat surfaces, called facets. Faceting bring out the brilliance and sparkle of gemstones. Faceted gemstones show flashes of color and play of light within them.