Tugarinovite

(repeating unit)MoO₂IMA symbolTug^[1]Strunz classification4.DB.05Crystal systemMonoclinicCrystal classPrismatic H-M symbol (2/m)Space groupP2₁/c (no. 14)Unit cella = 5.6 Å, b = 4.85 Å, c = 5.53 Å; β = 119.37°IdentificationColorDark lilac-brownCrystal habitCrystals are tabular striated prismsTwinningPolysyntheticMohs scale hardness4.6LusterGreasy to metallicStreakGreenish grayDiaphaneitySemitransparentSpecific gravity6.58 (calculated)Optical propertiesBiaxialPleochroismLight gray to dark pink; pale yellow to bluish olive-brown in reflected lightReferences^[2][3][4]

Tugarinovite is a rare molybdenum oxide mineral with formula MoO₂. It occurs as a primary mineral phase associated with metasomatism in a sulfur deficient reducing environment. In the type locality it occurs with uraninite, molybdenite, galena, zircon and wulfenite.^[2]

Tugarinovite was first described for an occurrence in the Lenskoye molybdenum–uranium deposit in the Amurskaya Oblast, Far-Eastern Region, Russia. It was named for geochemist Ivan Alekseevich Tugarinov of the Vernadskii Institute in Moscow.^[2][3] In addition to its type locality in Russia it has been reported from the Allende meteorite in Chihuahua, Mexico, the Nansei Archipelago of Japan and Bohemia in the Czech Republic.^[3]