Class : Silicates
    Subclass : Phyllosilicates
    Crystal system : Monoclinic
    Chemistry : (Mg,Al)₂Si₄O₁₀(OH) 4H₂O
    Rarity : Uncommon

Palygorskite (or attapulgite) is a hydrated aluminum and magnesium silicate close to serpentines. It is a magnesium silicate weathering mineral, known from many environments. It is found in contexts of serpentinized ultrabasic rocks, in maerls and metamorphic dolomites, but also in hydrothermal veins or granitic pegmatites. It is also found in soils and sediments deriving from the alteration of these rocks, especially in arid and semi-arid regions. Its name comes from its locality of discovery : Palygorskaya (Russia). It is presented in tangled cryptocrystalline fibers, giving rise to light porous masses, hence the name "mountain leather" or "mountain wool" which is sometimes given to it. Note, however, that "mountain cardboard" can also designate very light porous aggregates of sepiolite fibers. These felted aggregates have an appearance reminiscent of cardboard sheets, tear like cardboard, and can reach large dimensions. However, we also know of rare crystals visible to the naked eye of palygorskite : these are very thin strips which do not exceed a centimeter. It is usually a brown color reminiscent of aged leather, palygorskite can also be white, gray, yellowish or greenish gray. It is a material widely used as thermal and sound insulation in the building industry. In the chemical industry it serves as a filter and absorbent agent. Yucatan palygorskite, mixed with indigo, provided "Maya blue", a pigment very prized in the pre-Columbian era.

Main photo : Palygorskite from La Table, Savoie, France © Michel Arliguie

No twins known for this mineral species.

No fakes listed for this mineral species.