Lermontovite
Lermontovite is an IMA-recognized mineral species in the phosphate class, with the chemical formula U⁴⁺(PO₄)(OH)·H₂O.
It crystallizes in the orthorhombic crystal system (space group Ccca).
Key properties: specific gravity 4–4.5; Dull, silky on fractures luster; optically biaxial.
IMA symbol Ler, grandfathered status — known before the IMA’s founding, named in 1956.
Found in uranium-bearing veins in a granite porphyry stock.
It is found associated with Halloysite, vrbaite, lorandite, evansite, uraninite, marcasite, molybdenum sulfate.
The mineral was named to honor Mikhail Yur’evich Lermontov (1814–1841), Russian poet.
Index entry. This entry combines official IMA/RRUFF species data with published physical-property data — a full written entry hasn’t been published yet.
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