Scratching another stone with a suspect diamond is an excellent test of authenticity. Scratching determines the hardness of the stone, which is a key identifying characteristic for diamonds. More »

A common process for mining diamonds is to remove and process kimberlite ore. Kimberlite ore can be found in underground mines and open pits and often contains a small amount of diamonds that must be separated from the o... More »

To identify raw gemstones, observe their hue, tone and saturation. The transparency, size and heft of a gemstone influences its identification, as does its luster and optical phenomena. More » Beauty & Fashion Jewelry & Watches Precious Metals & Gems

Blowing breath onto a diamond, rubbing it with sandpaper, observing how it sparkles and how it refracts light are ways to determine its authenticity. Studying a diamond's imperfections is another technique, though this r... More »

Good diamond testers identify diamonds based on their electric conductivity instead of heat conductivity. Testers that identify both properties are even more accurate. In addition, a good diamond detector should notify t... More » Beauty & Fashion Jewelry & Watches Precious Metals & Gems

A system developed by the Gemological Institute of America in the 1950s that grades diamonds by color, clarity, cut and carat weight determines a diamond's price. The value is affected by the quality and rarity of the fo... More »

A diamond grading chart is a rating system for the internal characteristics and surface conditions of diamonds developed by the GIA, an independent non-profit laboratory that rates and certifies diamonds. The chart consi... More » Beauty & Fashion Jewelry & Watches Precious Metals & Gems