What is a Gemstone?

A Gemstone is a mineral that has the qualities of being beautifully colored, hard, durable, and RARE!

Found in its natural state, gemstones can be rather unremarkable. But when cut (faceted) and polished, it is a collector’s choice and can be used in jewelry. Not all gemstones are used for jewelry. Many are too soft, too fragile and are shown as exhibits in museums and sought after by collectors. Of the 2,000 minerals identified in the world, only about 16 can be used as valuable gemstones.

What gives Gemstones their color?

Natural gemstones are mineral crystals whose chemistry and structure give them color and character. The breath taking, awesome brilliantly shining characteristics of fine jewelry covered with beautifully colored gemstones are sought after worldwide and from ancient history they have been of greatest value.

Color is the most obvious and attractive feature of gemstones. I find this characteristic fascinating and complex. Light appears as white because the colors are not separated. If you look at sunlight as a mixture of different colors of light, and then imagine that light passing through a gemstone; you will understand that some of the colors of light are absorbed; some of the color or colors pass right through the gemstone. The colors of light are the colors of the rainbow: red, orange, yellow, green, blue, indigo, and violet. When light enters a faceted gemstone, it is bent to a different angle. This refraction of light is seen due to the facets on the outside of the gemstone, so positioned that the light enters the stone from the top, is then bent, and reflected back to the viewer displaying its brilliant color.

Why does a ruby appear red?  All the other colors of white light are absorbed, only the red light passes through and so the viewer is able to see the red ruby. If no light is absorbed, the stone appears colorless; all the white light passes through unchanged.

Some Gemstones are "self-colored" according to the characteristics of their chemical structure. These gemstones are rare.

Most gemstones are colored by impurities or trace elements in their crystal structure.

How the gemstones are cut and how they are shaped determine the color they reflect. A lapidary uses a variety of grinding wheels and grits to shape and polish the colored gems or stones. Gems are usually cut to highlight their internal color or natural crystal shape.

·         Opal stones have been cut into the shape of a dome, and then polished on the outer surface. This technique doesn't let the light shine through.

·         Transparent gems are cut with a method called faceting. A rough diamond stone is turned into its brilliant sparkle by grinding its flat, outside surfaces in a characteristic geometric pattern.

Heat changes the chemical state of an impurity to deepen or lighten color, an additional way gemstones acquire color. Less impurities will improve clarity, more impurities in the mineral will have a characteristic hue. The complex relationship between a chemical impurity and a gemstone color depend on the gemstones crystal structure and the trace elements in it.

http://www.wordiq.com/definition/Gemstones

Gemstone Jewelry at GemsSilverRings @ MB