Gemstone value of the stone. Some treatments are used widely because the resulting gem is stable, while others are not accepted most commonly because the gem color is unstable and may revert to the original tone. Heat can improve gemstone color or clarity. The heating process has been well known to gem miners and cutters for centuries, and in many stone types heating is a common practice. Most citrine is made by heating amethyst, and partial heating with a strong gradient results in “ametrine” – a stone partly amethyst and partly citrine. Aquamarine is often heated to remove yellow tones, or
Diamond (gemstone) to help authenticate Canadian diamonds. This is a very stringent tracking system of diamonds and helps protect the 'conflict free' label of Canadian diamonds. Currently, gem production totals nearly of cut and polished stones annually, and over of mined diamonds are sold for industrial use each year, as are about of synthesized diamond. Diamond (gemstone) A diamond (from the "adámas", meaning "unbreakable", "proper", or "unalterable") is one of the best-known and most sought-after gemstones. Diamonds have been used as decorative items since ancient times; some of the earliest references can be traced to 25,000 - 30,000 B.C. The hardness of