Berthierine Field of view 3.3 mm x 2.5 mm Locality Poudrette quarry (De-Mix quarry; Demix quarry; Uni-Mix quarry; Carrière Mont Saint-Hilaire; MSH), Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Québec, Canada Description Small part of an old Ron Waddell specimen. Visually confirmed by Dr. Andre Lalonde. — Photo: Modris Baum · Public domain
Berthierine
An iron-rich member of the serpentine-kaolinite family, commonly found in ironstones and low-temperature hydrothermal settings.
Intro adapted from Wikipedia (CC BY-SA).
Berthierine is an IMA-recognized mineral species in the silicate class, with the chemical formula (Fe²⁺,Fe³⁺,Al)₃(Si,Al)₂O₅(OH)₄.
It crystallizes in the orthorhombic crystal system. It is a member of the Serpentine, Clay structural group.
Key properties: specific gravity 3.06.
IMA symbol Brh, grandfathered status — known before the IMA’s founding, named in 1832.
Common in unmetamorphosed marine sediments; in lateritic and polar soils.
It is found associated with Glauconite, chlorite-vermiculite interstratified with mica-smectite, siderite, calcite.
The mineral was named to honor the French geologist, Pierre Berthier (1782–1861).