mineral

Olivine (peridot) crystal

Olivine group, (Mg,Fe)₂SiO₄; likely forsterite–fayalite solid solution

AI-generated identification · may be incorrect

Olive-green, translucent to opaque, with a glassy luster and granular, fractured surfaces; orthorhombic crystal structure, poor cleavage, Mohs hardness 6.5–7, specific gravity about 3.2–4.4.

Identified October 15, 2026More mineral →

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Physical properties

Olive-green, translucent to opaque, with a glassy luster and granular, fractured surfaces; orthorhombic crystal structure, poor cleavage, Mohs hardness 6.5–7, specific gravity about 3.2–4.4.

Formation & geological history

Olivine crystallizes from magnesium- and iron-rich magma, especially in basalt and mantle rocks; it also occurs in some meteorites. The specimen’s age and exact source cannot be determined from the image.

Uses & applications

Gem-quality transparent olivine is cut as peridot; less-clear material is collected or used in refractory products and foundry sands.

Geological facts

Olivine is a major mineral of Earth’s upper mantle, and peridot is its gem-quality variety.

Field identification & locations

The olive-green color and glassy, granular appearance are characteristic, but identification is best confirmed by hardness and mineral testing. Common sources include basaltic rocks, peridotite, and deposits in Arizona, Hawaii, Pakistan, and Egypt.