Amphibole

Amphibole is a group of   inosilicate minerals. They form prism or needlelike crystals. Many of them are asbestos.

They are double chain  tetrahedra, linked at the vertices. Usually they contain ions of iron and/or magnesium in their structures. Amphiboles can be green, black, colorless, white, yellow, blue, or brown.Mindat, Amphibole Supergroup

 References 

Category:Asbestos
Category:Inosilicates