Brief Description: Its name probably derives from the Arabic word talq = pure (white) due to the colour of its powder. Its chemical formula is Mg3Si4O10(OH)2 and it belongs to the Phylosilicates category. Its lustre is pearly, sebaceous or dull. Its colour ranges from light-green, white to grey. Sometimes, it can be yellowish, reddish or brown, because of its mixture of iron oxides. Its specific gravity is 2.7 ? 2.8 and it is semi-transparent. Its hardness is 1 and it is the softest mineral in Mohs scale. It has a slightly higher hardness 1½ - 2½ in the solid variety of steatite, while its fusibility is 5. The crystals are rarely tabular or pseudo-hexagonal. It usually occurs in foliated masses or foliated radial aggregates, as well as granular and solid masses. Talc is a secondary mineral, alteration product of ultramafic rocks components. Talc has many appliances, with primarily the powder manufacture. It has low thermal and electrical conductivity, it is fire-resistant and is not attacked by acids. For these reasons, it has several industrial appliances, e.g. pharmaceutics, chromatics, elastics, ceramics and pesticides industry and elsewhere. 
Bibliography: Ευρετήριο ορυκτών ΑΠΘ στην ιστοσελίδα http://www.geo.auth.gr/106/az_gr.htm Τσιραμπίδης Α. (2005). Ο ορυκτός πλούτος της Ελλάδας. Εκδόσεις Γιαχούδη Θεσσαλονίκη, σελ. 391. Berry, L.G., Mason, B. and Dietrich, R.V. (1983). Mineralogy. W. H. Freeman and Company, San Francisco, 561 pp.