Originally Posted by
AlexCraig
Colour: Dark green, pale to dark brown depending on iron content
Lustre; opacity: Vitreous to silky; translucent to transparent
Streak: White
Hardness: 5-6
Specific gravity: 3.1-3.6 (increasing with iron content)
Cleavage; fracture: two good cleavages at about 120 degrees; splintery
Habit: Individual cryatals rare; aggregates of rodlike or fiberous crystals, often radiating
Crystal system: Monoclinic
(Minerals and Gemstones: 300 of the Earth's natural treasures, page 252.)
Connect With Us