Complete mineralogical data for OPAL. Chemical Formula: SiO2·nH2O. Crystal System: Amorphous. Learn about its geologic occurrence, habit, and identification.

Complete mineralogical data for OPHIRITE. Chemical Formula: Ca2Mg4Zn2Mn3+2(Fe3+W9O34)2(H2O)2·46H2O. Crystal System: Triclinic. Learn about its geologic occurrence, habit, and identification.

Complete mineralogical data for OPPENHEIMERITE. Chemical Formula: Na2(UO2)(SO4)2(H2O)3. Crystal System: Triclinic. Learn about its geologic occurrence, habit, and identification.

Complete mineralogical data for OLKHONSKITE. Chemical Formula: (Cr,V)2Ti3O9. Crystal System: Monoclinic. Learn about its geologic occurrence, habit, and identification.

Complete mineralogical data for OLMIITE. Chemical Formula: CaMn2+[SiO3(OH)](OH). Crystal System: Orthorhombic. Learn about its geologic occurrence, habit, and identification.

Complete mineralogical data for OLMSTEADITE. Chemical Formula: KFe2+2Nb(PO4)2O2(H2O)2. Crystal System: Orthorhombic. Learn about its geologic occurrence, habit, and identification.

Complete mineralogical data for OLSACHERITE. Chemical Formula: Pb2(Se6+O4)(SO4). Crystal System: Orthorhombic. Learn about its geologic occurrence, habit, and identification.

Complete mineralogical data for OLSENITE. Chemical Formula: KFe4(PO4)3. Crystal System: Orthorhombic. Learn about its geologic occurrence, habit, and identification.

Complete mineralogical data for OLSHANSKYITE. Chemical Formula: Ca2[B3O3(OH)6]OH·3H2O. Crystal System: Triclinic. Learn about its geologic occurrence, habit, and identification.

Complete mineralogical data for OLYMPITE. Chemical Formula: Na5Li(PO4)2. Crystal System: Orthorhombic. Learn about its geologic occurrence, habit, and identification.