Asbestos, tremolite (CAS NO.77536-68-6) is a member of the amphibole group of silicate minerals with composition: Ca₂Mg₅Si₈O₂₂(OH)₂. Tremolite forms by metamorphism of sediments rich in dolomite and quartz. Tremolite forms a series with actinolite and ferro-actinolite. Pure magnesium tremolite is creamy white, but the color grades to dark green with increasing iron content. It has a hardness on Mohs scale of 5 to 6. Nephrite, one of the two minerals of the gemstone jade, is a green variety of tremolite.

A fibrous variety of Asbestos, tremolite (CAS NO.77536-68-6) is used as asbestos. This material is toxic and inhaling the fibers can lead to asbestosis, lung cancer and mesothelioma.
Tremolite is an indicator of metamorphic grade since at high temperatures it converts to diopside. Calcite, grossular, talc, and serpentine are common associates of tremolite.

IARC Cancer Review: Human Sufficient Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 14 (1977),p. 11.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) ; Animal Sufficient Evidence IMEMDT    IARC Monographs on the Evaluation of Carcinogenic Risk of Chemicals to Man . 14 (1977),p. 11.(World Health Organization, Internation Agency for Research on Cancer,Lyon, France.: ) (Single copies can be ordered from WHO Publications Centre U.S.A., 49 Sheridan Avenue, Albany, NY 12210) .

Confirmed human carcinogen with experimental tumorigenic and neoplastigenic data.
Analytical Methods: 
For occupational chemical analysis use NIOSH: Fibers, 7400; Asbestos Fibers, 7402.

OSHA PEL: TWA 2 million fibers/m³; CL 10 million fibers/m³; Cancer Hazard
ACGIH TLV: TWA 0.1 fibers/cc; Confirmed Human Carcinogen
DFG MAK: DFG TRK: (Fine dust particles that are able to reach the alveolar area of the lung) 1 × 10⁶ fibers/m³ (0.05 mg/m³), applicable when there is more than 2.5% asbestos in the dust
NIOSH REL: (asbestos): 0.1 fb/cc in a 400 L air sample
DOT Classification:  9; Label: CLASS 9

For occupational chemical analysis use NIOSH: Fibers, 7400; Asbestos Fibers, 7402.

 Asbestos, tremolite ,its CAS NO. is 77536-68-6,the synonyms is Fibrous tremolite ; NCI-C08991 ; Tremolite asbestos ; Tremolite ; Tremolite asbestos .