ACTINOLITE
Actinolite in Talc from Lake Wenatchee, Washington state, USA
Actinolite crystals form as long, bladed specimens, commonly twinned. Actinolite may be in lamellar and columnar aggregates, often radiating, and in massive, fibrous, or granular habits. The colour is light to blackish green. The streak is white. Actinolite is transparent to nearly opaque, and has a vitreous lustre. A compact variety is called nephrite, a form of jade. It forms in schists and amphibolites, commonly from the metamorphism of basic igneous rocks.
Composition: Ca2(Mg,Fe)5Si8O22(OH)2
Hardness: 5-6
Specific Gravity: 3.0-3.44
Cleavage: Good
Fracture: Uneven to subconchoidal.
see here for talc.