When we hear the word "gemstone" we commonly think of such thing as rubies or diamonds used to make jewelry. These beautiful and precious stones, also known by the shorter name "gems", are the stuff of fairytale necklaces and bracelets worn by the rich and famous. But gemstones have a long history of use in many forms, modern jewelry notwithstanding, and their history goes back thousands of years.
In the most ancient of days, gemstones were commonly used as a medium for artwork. Carved and engraved gems were fashioned into individual artistic pieces or included in much larger pieces. These pieces were found in the homes and palaces of great kings and princes.
Gemstones also had great value in terms of their religious significance. For example, the Jewish Torah speaks of the great historical leader, Moses, making a breastplate for his high priest that contained 12 precious gemstones. Each one was to signify one of the 12 tribes of Israel. Babylonian, Egyptian, and Syrian priests were also known to use gemstones as part of their ceremonial garb.
Gemstone Divisions
Today, gemstones are classified as either precious or semi-precious; a classification system dating back to ancient Greece. Gemstones of both classifications are used not only for jewelry and art, but also in a wide range of industrial and technical applications. And they remain just as popular and costly as they've ever been.
In order to distinguish between the many different variations of similar gemstones, the two classifications are further divided into species and varieties. For example, the beryl species is subdivided into six different varieties - the most common being emerald and red beryl. Another example is corundum. The red variety of this mineral is known as ruby, while all other colors are considered sapphire.
Gemstone Grading
With the exception of diamonds, different jewelers and gem cutters grade their gemstones using different criteria. Unfortunately, there is no universal grading standard that everyone agrees on. That said, there are four distinct things jewelers look for when grading gemstones: cut, color, clarity, and carat. These criteria are what are known in the history as the "four Cs".
The importance of each of these criteria depends on the stone in question. For instance, cut is the most important for a white diamond, followed by clarity and color. For a ruby, color would be the most important aspect in order to distinguish it from sapphire. In either case, how well a particular gemstone is graded plays heavily into its market price.
Improving Natural Gemstones
Natural gemstones look very different in raw form than in the jewelry store. Cutting and polishing are the two main steps to improving the appearance of gems for cosmetic use, but a third process, which involves heating the minerals at various temperatures, is also used to improve both color and clarity.
Stone cutters and jewelers hone their skills over many years to create the finest gems; and with great result. From diamonds to rubies to emeralds, gemstones please the eye like very few things.
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