General Information: Chemical Formula:Ca2(Mg,Fe++)5Si8O22(OH)2
Composition:(Molecular Weight = 875.45 gm)
Calcium 9.16 %
CaMagnesium 8.33 %
MgIron 12.76 %
FeSilicon 25.66 %
SiHydrogen 0.23 %
H Oxygen 43.86 %
O Empirical Formula: Ca2Mg3Si8O22(OH)2Fe2+2
Environment:Metamorphic rocks.
IMA Status:Approved IMA 1978
Locality:Common world wide.
Name Origin:From the Greek, aktinos, meaning "ray" in allusion to actinolite's fibrous nature.
Physical Properties: Cleavage:[110] Perfect, [110] Perfect
Color:green, green black, gray green, or black.
Density:2.98 - 3.1, Average = 3.04
Diaphaniety:Translucent to transparent
Habits:Bladed - Aggregates of thin lath-like crystals (e.g. kyanite)., Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite), Fibrous - Crystals made up of fibers.
Hardness:5.5 - Knife Blade
Luminescence:Non-fluorescent.
Luster:Vitreous (Glassy)
Streak:white
More details...
ACTINOLITE. ATTINOLITE