How do I identify Omphacite?

Omphacite can be identified by its hardness of 5 - 6 on the Mohs scale, dark green color. Look for these key characteristics when examining specimens.

What color is Omphacite?

Omphacite typically appears in dark green. Color can vary depending on impurities and formation conditions.

How hard is Omphacite?

Omphacite has a hardness of 5 - 6 on the Mohs scale. This gives it moderate hardness.

Omphacite

A variety of Minerals

What is Omphacite?

Omphacite is a member of the clinopyroxene group of silicate minerals with formula: (Ca, Na)(Mg, Fe, Al)Si2O6. It is a variably deep to pale green or nearly colorless variety of clinopyroxene. It normally appears in eclogite, which is the high-pressure metamorphic rock of basalt. Omphacite is the solid solution of Fe-bearing diopside and jadeite. It crystallizes in the monoclinic system with prismatic, typically twinned forms, though usually anhedral. Its space group can be P2/n or C2/c depending on the thermal history. It exhibits the typical near 90° pyroxene cleavage. It is brittle with specific gravity of 3.29 to 3.39 and a Mohs hardness of 5 to 6.

Etymology & Origins

It was first described in 1815 in the Münchberg Metamorphic complex, Franconia, Bavaria, Germany. The name omphacite derives from the Greek omphax or unripe grape for the typical green color.

Optical Properties

Refractive Index: 1.662-1.723
Pleochroism: Weak: colorless, very pale green, very pale green, blue-green
Optical Character: Biaxial positive

Omphacite Market Value Calculator

Estimate the market value of Omphacite using size, quality, and finish. This preview calculator is for quick context and is not a formal appraisal.

Omphacite Localities Map

See where Omphacite is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.

Map preview

North ZoneCentral RidgeSouth Basin

The Meaning

Omphacite is often thought to be a type of jade, and as such, throughout history, it was believed to have the same benefits. It was traditionally thought of by the Mayans and Aztecs as a pain reliever. The Chinese have long believed that omphacite (or Jade) is a heavenly stone that can bring about prosperity whilst shielding its wearers from bad spirits.

Key Characteristics

Composition of Omphacite

Omphacite is the solid solution of Fe-bearing diopside (CaMgSi2O6) and jadeite (NaAlSi2O6). Depending on how much the coupled substitution of (Na, Al)-(Mg-Fe, Ca) happens, the chemical composition of omphacite varies continuously from pure diopside to pure jadeite. Due to the relatively small radius of (Na, Al) atoms, the unit cell volume linearly decreases as jadeite component increases. In addition, the coupled substitution also stiffens the crystals. The bulk and shear modulus linearly increases as jadeite component increases.