Eosphorite Locality: Taquaral , Itinga , Jequitinhonha valley, Minas Gerais , Southeast Region, Brazil ( Locality at mindat.org ) Size: 4.5 x 2.8 x 2.4 cm. A rich carpet of translucent-to-transparent, coffee-colored crystals of eosphorite (Hydrated Manganese Iron Aluminum Phosphate Hydroxide), which came out of the Mauthner collection after being previously in the collection of ROM curator, Ian Nicklin. These little crystals are arranged in pretty bursts richly covering most of one side of the matrix. Old material from the 1960s or 1970s. — Photo: Robert M. Lavinsky · CC BY-SA 3.0
Eosphorite
A brown-to-pink hydrated manganese-aluminium phosphate occasionally cut as a collector's gem.
Intro adapted from Wikipedia (CC BY-SA).
Eosphorite is an IMA-recognized mineral species in the phosphate class, with the chemical formula Mn²⁺Al(PO₄)(OH)₂·H₂O.
It crystallizes in the orthorhombic crystal system (space group Bbam). It is a member of the Childrenite structural group.
Key properties: Mohs hardness 5; specific gravity 3.06–3.08; White streak; Vitreous to resinous luster; refractive index 1.651; optically biaxial.
IMA symbol Eos, grandfathered status — known before the IMA’s founding, named in 1878.
Typically a secondary mineral in some phosphate-bearing granite pegmatites.
It is found associated with Rhodochrosite, lithiophilite, triploidite, dickinsonite (Branchville, Connecticut, USA); albite, cookeite, apatite, beryllonite, hydroxyl-herderite.
Its name comes from the Greek for dawn-bearing, in allusion to the pink color.