Aegirine

Lustre: Vitreous to slightly resinous.
Hardness: Mohs 6 — about as hard as a steel knife.
Streak: Yellowish-grey.
Habit: Monoclinic crystal system.

Colour	Black, Green
Mohs hardness	6
Lustre	Vitreous to slightly resinous
Streak	Yellowish-grey
Crystal system	Monoclinic
Transparency	Translucent to opaque
Cleavage	Good on {110}, (110) ^ (10) ≈87°; parting on {100}
Fracture	Uneven
Specific gravity	3.50–3.60

What is Aegirine?

Aegirine is a mineral. It is a member of the clinopyroxene group of inosilicate minerals. Acmite is a fibrous green-colored variety of aegirine, with the name also used as a synonym. It was first described in 1821, in Kongsberg, Norway.