Chemical Formula CaMgSi2O6
Color Green, Yellow, Brown, Black
Hardness 5 – 6
Crystal System Monoclinic
Refractive Index 1.665 – 1.730
SG 3.3 – 3.5
Transparency Transparent. Star Diopside is opaque.
Double Refraction 0.028
Cleavage 1,2 – prismatic. May also exhibit parting in one direction.
Mineral Class Diopside
Although Diopside occurs in a variety of colors, the green color is the most common form. A purple type known as Violane is occasionally used as a gemstone, and Star Diopside is very dark green to black. But the form of this stone that puts this gemstone on the map is the deep green Chrome Diopside form.
Chrome Diopside in limited quantity is known from several localities, but a large commercially exploitable deposit discovered in Siberia in 1988 made this gemstone readily available to the market. Since then, Pakistan has also become a signficant producer of Chrome Diopside. Chrome Diopside is an affordable gemstone that has an intense forest-green color which rivals that of more expensive Tsavorite and Green Chrome Tourmaline.
Deep green color combined with transparency give a stone more value. Except in lighter colored stones, the faceting of larger cuts is generally avoided because the deep green color tends to make its tone too black. Careful cutting is also necessary in larger stones to keep the facet angles shallow to improve brilliance. The deep green color of Chrome Diopside is natural and not enhanced.
Chrome Diopside is faceted into gemstone cuts mainly for earrings and pendants. It is generally not used for rings and bracelet due to its low hardness. Star Diopside and the purple variety Violane are faceted into cabochons mostly as collectors gems.
Chrome Diopside – Deep forest-green variety of Diopside. Its color is caused from traces of the element chromium.
Star Diopside – Diopside polished into a cabochon that displays asterism in the form of a four-rayed star. Its colors is usually very dark green to black.
Tashmarine Diopside – Light yellowish-green form of Diopside from a recently exploited deposit in eastern Uzbekistan. This term was recently coined by the Columbia Gem House company in Vancouver.
Violane – Light blue to purple, manganese-rich variety of Diopside.Diopside gemstones are natural and not heated or enhanced.Diopside of facetable nature comes from Italy, Austria, Finland, Tanzania, Madagascar, Mynamar (Burma), China, and the U.S. (New York). The source of most gem is from Russia, but other deposits also exist in Pakistan, Afghanistan, and Finland. Violane is primarily from Italy, and Star Diopside from India.Chrome Diopside has a similar color to both Tsavorite and Chrome Tourmaline, but is softer than those gemstones. The color is also a more forest-green hue than Emerald.
Dumortierite is a minor blue gemstone that usually forms as inclusions in Quartz. Its most common color is blue or grayish-blue, though pink and purple colors are also known. Dumortierite’s durability, combined with a high hardness, would make this an ideal gemstone, but the lack of transparency and often dull luster limit its use.
Diopside TREATMENTS AND ENHANCEMENTS