Brief Description: Its name derives from the Latin term granatus = pomegranate, because of the crystals? similarity in shape and colour to pomegranate seeds. In ancient times, it was known as anthrax, name given to red gemstones. Its chemical formula is X32+Υ23+(SiO4)3 [(X=Mg, Fe, Mn, Ca), (Y=Al, Cr, Fe)] and it belongs to the category Nesosilicates. Its lustre is vitreous or resinous. Its colour depends on the composition. The most common is red or reddish-brown. Transparent, semitransparent. Its specific gravity ranges from 3.5 - 4.3 and depends on the composition. Its hardness is 6½ - 7½ and its fusibility 3 - 3.5 (except for uvarovite, which is infusible. The crystals are rhombic dodecahedra or icositetrahedra. In rounded grains and granular aggregates. They alter to talc, chlorite, serpentine, scapolite, calcite and limonite. They are used as abrasives (because of hardness) and some clear coloured varieties as gemstones. They are typical minerals of transformed rocks and occasionally occur in igneous rocks as well. 
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. Σαπουντζής, Η. και Χριστοφίδης, Γ. (1985). Ορυκτοδιαγνωστική. University Studio Press, Θεσσαλονίκη, 241 σ.