". . . although actinolite is an intermediate member between magnesium-rich tremolite and iron-rich ferro-actinolite, in the magnesium-iron-rich amphibole series, all three amphiboles are often simply referred to as tremolite-actinolite and we followed this convention." [Reference #1]
"Health research has focused on the three main commercial types of asbestos (chrysotile, crocidolite, and amosite), all of which were mined in South Africa. The health effects of other asbestiform amphiboles, including tremolite, actinolite, richterite, winchite, and anthophyllite, have been less researched, although there is strong evidence that they, too, cause disease. [Reference #1] See "Iron." See "Asbestos."