A. fluorite
B. mica
Correct answer: b
Talc is a hydrothermal altered mineral. Magnesium-rich minerals often become talc after hydrothermal alteration, so talc often presents mineral illusions such as olivine, pyroxene, amphibole and tremolite. Talc is a common silicate mineral, which is very soft and greasy. People used to choose 10 minerals to represent the hardness grade of 10, which is called Mohs hardness. In this 10 grade, the first one (that is, the softest one) is talc. Soft talc can be used to draw white spots instead of chalk. Talc is generally in the form of blocks, leaves, fibers or radiations, and its color is white and off-white, which will show various colors due to other impurities. Talc has many uses, such as refractories, paper, rubber fillers, pesticide absorbents, leather coatings, cosmetics and carving materials.