CAS registry numbers (CAS No.) and chemical formulas of asbestos fibre

Chrysotile or white asbestos has CAS No. 12001-29-5, and be given a chemical formula of Mg3[Si2O5](OH)4

Amosite or brown asbestos has CAS No. 12172-73-5, is a trade name for the amphiboles belonging to the Cummingtonite – Grunerite solid solution series, commonly from Africa, named as an acronym from Asbestos Mines of South Africa. One formula given for amosite is Fe7Si8O22(OH)2.

Crocidolite or blue asbestos has CAS No. 12001-28-4 is an amphibole found primarily in southern Africa, but also in Australia. It is the fibrous form of the amphibole riebeckite. One formula given for crocidolite is Na2Fe2+3Fe3+2Si8O22(OH)2.

Other regulated asbestos minerals, such as tremolite asbestos has CAS No. 77536-68-6. One formula given for tremolite is Ca2Mg5Si8O22(OH)2

Actinolite asbestos (or smaragdite) has CAS No. 77536-66-4 and one formula given for actinolite is Ca2(Mg, Fe)5(Si8O22)(OH)2.
Anthophyllite asbestos has CAS No. 77536-67-5. One formula given for anthophyllite is (Mg, Fe)7Si8O22(OH)2.

Source of wikipedia.com