It is interesting to study the origin of gems and their discovery, which makes a fascinating story. Gemstones are actually minerals found in rocks with a certain quality and intrinsic value. When rocks (igneous metamorphic or sedimentary) change due to the intense heat and pressure within the earth, new rocks with minerals are formed which often have gemstones in them.

There are a hundred different types of gems found on the earth's surface. They are classified depending upon their clarity and their chemical characteristics.

Specific types of gems are associated with specific rock types. To be specific, the sources of colored gems are in sedimentary deposits, such as gravel beds, while marbles and some other types of gems are found in metamorphic rocks. They are then cut, polished and fashioned to make jewelry or other adornments. The brilliant colors of the gemstones are due to the metallic ions in the composition of the gems.

However there are certain rocks that are not minerals yet considered to be gemstones, such as lapis-lazuli, Amber or Jet.

Over the years gemstones have been classified as precious and semi precious. Primarily diamond, ruby, sapphires, emerald are considered precious. Over the years pearl, opal and amethyst have been included in the "precious" category, and the others such as Jade, Onyx, Agate, and Turquoise are semi precious. There are of course a hundred other varieties.

There are Organic gems too, formed from plants and animals. Pearls are formed inside the freshwater shell fish when irritants get inside them. Coral is formed from skeletons of marine animals. Amber is made from fossilised tree resin, and Jet is fossilised wood.

Imitation gemstones are also available in plenty now, which look like the original but have neither their chemical nor physical characteristics. There are various processes to check the authenticity of the gems, which help in recognizing their worth. Most commonly - the four C's (color, cut, clarity and carat). This was basically introduced for the customer, to understand the quality of the gems.

Whatever the origins, Gems are prized possessions - and has been for centuries.