Enstatite

About it

Magnesium orthopyroxene, grey-green to bronzy brown, in peridotite, norite, and meteorites; bronzite has a metallic shimmer. Gem crystals come from Tanzania and Sri Lanka.

Type

Mineral

Group

Silicate (inosilicate), pyroxene group

Formula

Mg2Si2O6

Hardness (Mohs)

5–6

Specific gravity

3.2–3.4

Streak

white to grey

Lustre

vitreous (glassy), pearly

Crystal system

Orthorhombic

Colours

colourless, grey, green, brown, yellowish

Transparency

transparent, translucent, opaque

Cleavage and fracture

good in two directions at nearly 90°

Typical values: real specimens vary. For more, see mindat.org.