Palygorskite: Gemstone Information
Palygorskite is (Mg,Al)2Si4O10(OH)4H2O and usually occurs as fibrous mats often called ‘mountain leather’. The crystal system is monoclinic with a hardness of 2–2.5 and SG 2.0–2.6. The colour may be white, grey, shades of pink or yellowish and the RI is near 1.55. This, when observed, may arise from quartz which is frequently used to impregnate the soft palygorskite.Palygorskite is an alteration product of magnesium silicates in soils and sediments, and occurs in hydrothermal veins. Locations include Attapulgus,Georgia and Sapillo, New Mexico, as well as Palygorskaya, Perm, Russia.