O Oberthürite (IMA2017-072) 2.0 [no] [no] Oberwolfachite (alunite: IMA2021-010) [no] [no] Oboyerite (tellurite-tellurium oxysalt: IMA1979-009) 4.JN.25 (IUPAC: hexahydrogen hexalead tritellurate(IV) dihexaoxotellurate(VI) dihydrate) Obradovicite (heteropolymolybdate, betpakdalite) 7.GB.40 Obradovicite-KCu (IMA2010-E, IMA1978-061) 7.GB.40 Obradovicite-NaCu (IMA2011-079) 7.GB.40 [no] [no] Obradovicite-NaNa (IMA2011-046) 7.GB.40 [no] [no] O'danielite (alluaudite: IMA1979-040) 8.AC.10 (Na☐ZnZn2[AsO4][AsO3(OH)]2) Odigitriaite (IMA2015-028) 9.E?. [no] [no] (IUPAC: caesium pentasodium pentacalcium [diboron octatriacontaoxotetradecasilicate] difluoride) Odikhinchaite (eudialyte: IMA2020-064) 9.CO. [no] [no] Odinite (serpentine: IMA1988-015) 9.ED.05 Odintsovite (IMA1994-052) 9.CJ.50 [no] Oenite (loellingite: IMA1995-007) 2.EB.10f Offretite (zeolitic tectosilicate: IMA1997 s.p., 1969) 9.GD.25 (IUPAC: potassium calcium magnesium (pentaalumotridecasilicate) hexatriacontaoxy pentadecahydrate) Oftedalite (milarite: IMA2003-045a) 9.CM.05 Ogdensburgite (IMA1980-054) 8.DC.57 (IUPAC: dicalcium tetrairon(III) zinc hexahydro tetrarsenate hexahydrate) Ognitite (IMA2018-006a) 2.0 [no] [no] [no] (IUPAC: nickel bismuth telluride) Ohmilite (IMA1974-031) 9.DH.10 Ojuelaite (arthurite: IMA1979-035) 8.DC.15 (IUPAC: zinc diiron(III) dihydro diarsenate tetrahydrate) Okanoganite-(Y) (okanoganite: IMA1979-048) 9.AJ.35 Okayamalite (melilite: IMA1997-002) 9.BB.10 [no] (IUPAC: dicalcium diboron heptaoxosilicate) Okenite (Y: 1828) 9.EA.40 (IUPAC: decacalcium hexatetracontaoxoctadecasilicate octadecahydrate) Okhotskite (IMA1985-010a) 9.BG.20 Okieite (decavanadate: IMA2018-080) 4.0 [no] [no] Okruschite (roscherite: IMA2013-097) 8.0 [no] [no] (IUPAC: dicalcium pentamanganese(II) tetraberyllium tetrahydro hexarsenate hexahydrate) Oldhamite (galena, rocksalt: 1863) 2.CD.10 (IUPAC: calcium sulfide) Oldsite (IMA2021-075) 7.EC. [no] [no] Olekminskite (IMA1989-047) 5.AB.40 (IUPAC: distrontium dicarbonate) Olenite (tourmaline: IMA1985-006) 9.CK.05 Olgite (aphthitalite: IMA1979-027) 8.AC.40 Olivenite (andalusite: 1820) 8.BB.30 (IUPAC: dicopper hydroxide arsenate) Olkhonskite (schreyerite: IMA1993-035) 4.CB.35 (IUPAC: dichromium trititanium nonaoxide) Olmiite (IMA2006-026) 9.AF.90 [no] (IUPAC: calcium manganese [hydrotrioxosilicate] hydroxide) Olmsteadite (IMA1974-034) 8.DJ.05 (IUPAC: potassium diiron(II) niobium dioxo diphosphate dihydrate) Olsacherite (baryte: IMA1969-009) 7.AD.35 (IUPAC: dilead (tetraoxoselenate(VI)) sulfate) Olshanskyite (IMA1968-025) 6.CA.55 Olympite (IMA1979-065) 8.AA.30 (IUPAC: lithium pentasodium diphosphate) Omariniite (IMA2016-050) 2.0 [no] [no] (Cu8Fe2ZnGe2S12) Omeiite (löllingite: IMA1985-xxx, 1978) 2.EB.15a (IUPAC: osmium diarsenide) Ominelite (IMA1999-025) 9.AJ.05 [no] (IUPAC: iron(II) trialuminium dioxy trioxoborate tetraoxysilicate) Omongwaite (IMA2003-054b) 7.CD.65 (IUPAC: disodium pentacalcium hexasulfate trihydrate) Omphacite (pyroxene: IMA1988 s.p.) 9.DA.20 Omsite (hydrotalcite: IMA2012-025) 4.FB. [no] (IUPAC: dinickel iron(III) hexahydroxide [antimony hexahydroxide]) Ondrušite (lindackerite: IMA2008-010) 8.CE.30 [no] [no] (IUPAC: calcium tetracopper diarsenate di(hydroxoarsenate(V)) decahydrate) Oneillite (eudialyte: IMA1998-064) 9.CO.10 [no] Onoratoite (IMA1967-032) 3.DC.80 (IUPAC: octaantimony undecaoxide dichloride) Oosterboschite (IMA1970-016) 2.BC.10 (IUPAC: hepta(lead,copper) pentaselenide) Opal (a mineraloid) (Y: old) 4.DA.10 [no] Ophirite (heteropolytungstate: IMA2013-017) 4.0 [no] [no] Oppenheimerite (IMA2014-073) 7.0 [no] [no] (IUPAC: disodium uranyl disulfate trihydrate) Orcelite (metalloid alloy: IMA1962 s.p., 1959) 2.AB.10 ( (x = 0.23)) Ordoñezite (tapiolite: 1955) 4.DB.10 (IUPAC: zinc diantimony(V) hexaoxide) Örebroite (welinite: IMA1985-039) 9.AF.75 Oregonite (IMA1962 s.p., 1959) 2.BB.05 (IUPAC: iron dinickel diarsenide) Oreillyite (nitride: IMA2020-030a) 1.0 [no] [no] (IUPAC: dichromium nitride) Organovaite (labuntsovite) 9.CE.30g Organovaite-Mn (IMA2000-031) 9.CE.30g [no] Organovaite-Zn (IMA2001-006)