Rockbridgeite is an anhydrous phosphate mineral in the "Rockbridgeite" supergroup with the chemical formula Fe2+Fe3+4(PO4)3(OH)5. It was discovered at the since-shut-down Midvale Mine in Rockbridge County, Virginia, United States. The researcher who first identified it, Clifford Frondel, named it in 1949 for its region of discovery, Rockbridge County.
{{Infobox mineral | name = Rockbridgeite | category = | boxwidth = 24 | boxbgcolor = | image =Phosphosiderite-Rockbridgeite-k330a.jpg | caption = | formula = Fe2+Fe3+4(PO4)3(OH)5 | IMAsymbol = Rkb | molweight = 648.96 g/mol | strunz = 8.BC.10 | dana = 41.9.2.1 | system = Orthorhombic | class = Dipyramidal (2/m2/m2/m) (same H-M symbol) | symmetry = Bbmm | color = Varies from green, to black, to brownish green, to reddish brown | habit = Euhedral crystals rare; typically fibrous in crusts, botryoidal and drusy masses | twinning = Cruciform twins possible | cleavage = Perfect on {100}, Distinct on {010}, Distinct on {001} | fracture = Uneven | tenacity = Brittle | mohs = 4.5 | luster = Vitreous to dull | refractive = Nx = 1.875, Ny = 1.880, Nz = 1.897 | opticalprop = Biaxial (+) | birefringence = 0.0220 | pleochroism = (x): light brown to light yellow-brown (y): bluish green. (z): dark bluish green. | streak = Greenish gray | gravity = 3.40 | melt = | fusibility = | diagnostic = | solubility = Soluble in HCl, but not in HNO3 or H2SO4 | diaphaneity = Subtranslucent | other = | references = }}
Rockbridgeite is an anhydrous phosphate mineral in the "Rockbridgeite" supergroup with the chemical formula Fe2+Fe3+4(PO4)3(OH)5. It was discovered at the since-shut-down Midvale Mine in Rockbridge County, Virginia, United States. The researcher who first identified it, Clifford Frondel, named it in 1949 for its region of discovery, Rockbridge County.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).