Is a Calcium Magnesium Sicate Hydroxide with formula:Ca2(Mg, Fe)5Si8O22(OH)2.
Hardness is 5-6.
The name comes from Tremola Valley, in St. Gottardo, Switzerland.
Tremolite belong to the series with Actinolite and Ferro-Actinolite, and when is pure without Iron, the color is white. In other case when Iron is contained the color will be brownish or greenish to dark green.
A fibrous mineral difficult to cut due to the splintery structure.