Actinolite is a mineral that commonly occurs in crystalline schists, often being the chief constituent of green-coloured schists and greenstones. It is used somewhat as an asbestos material. It has the formulae Ca2(Mg,Fe)5Si8O22(OH)2 (the same as nephrite, but being less attractive and harder to cut and polish is less valuable than nephrite) and a relative hardness of 6. Research Actinolite