Gemstone

admin — Tue, 01 Sep 2009 10:42:03 +0000

A gemstone (also called precious or semi-precious stones) is an attractive mineral, which, once cut and polished, is used to make jewelry or other jewelry. However certain rocks (such as lapis – lazuli) and organic materials (such as yellow or jet) are not minerals, but is still used in jewelry, and because it is often considered too precious stones . Most of the hard stone, but some soft minerals are used in jewelry because of flicker or physical properties that have aesthetic value. Rarity is another characteristic that gives value gems.

Classification
Gemstones are identified by gemologists, who describe the characteristics of diamonds and their use of technical terms specific to the field of gemology. The first characteristic a gemologist uses to identify a gemstone is its chemical composition. For example, diamonds are made of carbon (C) and rubies of aluminum oxide (Al2O3). In addition, many stones are crystals that are classified by crystal system such as cubic or trigonal or monoclinic. Another term used is habit, the shape of diamond is usually found in, for example diamonds, which has a cubic system, often found as octahedrons.

Gemstones are classified into different groups, species and varieties. For example, ruby is a variety of species corundum, while any other color of corundum is considered sapphire. Emerald (green), Aquamarine (blue), Red beryl (red), goshenite (no color), Heliodor (yellow), and Morganite (pink) are all varieties of the mineral species beryl.

Gems are characterized in terms of refractive index, dispersion, weight, hardness, cleavage, fracture, and luster. May they show pleochroism or double refraction. They may have luminescence and a characteristic absorption spectrum.

Defects in materials or stone can be present as inclusions.

Jewelry Review » Gemstone

Gemstone