Talc Talc Talc or talcum is a clay mineral composed of hydrated magnesium silicate with the chemical formula HMg(SiO) or MgSiO(OH). In loose form, it is (in ratio with or without corn starch) one of the most widely used substances known as baby powder. It occurs as foliated to fibrous masses, and in an exceptionally rare crystal form. It has a perfect basal cleavage, and the folia are not elastic, although slightly flexible. The Mohs scale of mineral hardness, based on scratch hardness comparison, defines value 1 as the hardness of talc. Talc can easily be scratched by a fingernail. Talc
Diamond simulant non-diamonds) fails, it may damage the simulant—an unacceptable outcome for most jewelry owners, as even if a stone is not a diamond, it may still be of value. Following are some of the properties by which diamond and its simulants can be compared and contrasted. The Mohs scale of mineral hardness is a non-linear scale of common minerals' resistances to scratching. Diamond is at the top of this scale (hardness 10), as it is one of the hardest naturally occurring materials known. (Some artificial substances, such as aggregated diamond nanorods, are harder.) Since a diamond is unlikely to encounter substances