Chrome diopside, a chromium-rich gem variety of Diopside, a pyroxene mineral. Diopside is an important rock forming mineral in several metamorphic and basic to ultra basic igneous rocks, also found in meteorites. Gemstone quality diopside can be very striking in appearance, and of interest to mineral collectors.

Chrome diopside has a deep green color due to the presence of chromium (also emerald's coloring agent) in its chemical composition. The crystals are very rare; the maximum size of them is about 10 cm. Chrome Diopside is highly refractive which gives it great sparkle. It steadily darkens as its size becomes larger. It is among the least expensive green gemstones. Chrome diopside is relatively soft, so it is better suited for use in pendants and earrings rather than rings and bracelets. Some specimens have been known to fluoresce.

Diopside is found all over the planet, but the rare top-gem-quality chrome diopside is found in eastern Siberia and is also known as Siberian Emerald. Chrome diopside is mined at one remote mountain location in a mineral-rich area known as Inagli in the state of Sakha (formerly Yakutia) which is best known for diamonds. Other occurrences of the mineral include Finland, Cuba, Mexico and Brazil; minor deposits are found in Kenya, Madagascar, New Zealand and Japan.

Characteristics:

Chemistry:  Ca(Mg,Fe,Cr)Si2O6
Class: silicates
Hardness (Mohs scale): 5.5. – 6.5
Density: 3.17 – 3.32
Refractive index: 1.669 – 1.702
Dispersion: none
Crystal system: monoclinic
Cleavage: distinct/good
Fracture: uneven
Transparency: transparent to translucent
Luster: vitreous