Penfieldite is a rare lead hydroxychloride mineral from the class of halides. It was named after Samuel Lewis Penfield. It has been a valid species before the founding of IMA, and was first published in 1892. It had been grandfathered, meaning the name penfieldite is still believed to refer to a valid species. When it was first described by Genth in 1892 from Laurion, Greece, the mineral had the formula of Pb3Cl4O.
via Wikipedia infobox
{{Infobox mineral|boxbgcolor=#52b4e7|image=Penfieldite-Boleite-Cotunnite-206830.jpg|formula=Pb2Cl3(OH)|IMAsymbol=Pfd|strunz=03.DC.15|system=Hexagonal|dana=10.04.01.01|class=Trigonal Dipyramidal H-M symbol: |symmetry=P|unit cell=5,360.83|molweight=537.77|color=Colorless, white, yellowish, bluish|cleavage=Distinct/good on {0001}|mohs=3–4|luster=Adamantine, greasy|opticalprop=Uniaxial (+)|refractive=nω = 2.130(1) nε = 2.210(1)|birefringence=0.080|streak=White|gravity=6.00|density=Measured: 5.82 – 6.61 Calculated: 6.00|solubility=Soluble in water|diaphaneity=Transparent}}
Penfieldite is a rare lead hydroxychloride mineral from the class of halides. It was named after Samuel Lewis Penfield. It has been a valid species before the founding of IMA, and was first published in 1892. It had been grandfathered, meaning the name penfieldite is still believed to refer to a valid species. When it was first described by Genth in 1892 from Laurion, Greece, the mineral had the formula of Pb3Cl4O.
Discovered by embedding cosine similarity (sentence-transformers MiniLM, 384-dim).