Sandstone (Red Arkose)
Sandstone (Arkose variant, primarily SiO2 with KAlSi3O8)
Category
Browse mineral composite specimens identified by the Rock Identifier community.
Sandstone (Red Arkose)
Sandstone (Arkose variant, primarily SiO2 with KAlSi3O8)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Volcanic Rock)
Peacock Ore
Bornite (Cu5FeS4) or iridescent Chalcopyrite (CuFeS2)
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
Granite
Phaneritic plutonic rock (Quartz, Alkali Feldspar, and Plagioclase)
Green Fluorite (likely synthetic or heat-treated for jewelry)
Calcium Fluoride (CaF2)
Limonite (Oxidized Iron Ore)
FeO(OH)·nH2O (Hydrous ferric oxide)
Sandstone
Arenite (SiO2 based with various mineral cements)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Limonite (Yellow Ochre)
Hydrated iron(III) oxide-hydroxides (FeO(OH)·nH2O)
Limonite (Iron Ore)
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
Limonite/Goethite Nodule
Iron Oxyhydroxide (primarily FeO(OH)·nH2O)
Granite
Granite (Felsic Intrusive Igneous Rock)
Sandstone (Ferruginous)
Arenite (Fe2O3 staining)
Diorite (River Rock/Cobble)
Intermediate Plutonic Igneous Rock (Diorite)
Gneiss
Gneiss (High-grade regional metamorphic rock)
Diorite
Phaneritic intermediate plutonic rock
Note regarding baguette production (not a rock)
Digital text image - Somali language
Epidote in Matrix
Epidote; Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
Arsenopyrite in Quartz Matrix
Arsenopyrite (FeAsS) with Quartz (SiO2)
Black Sand (Magnetite Sand)
Magnetite (Fe3O4)
Sandstone
Arenite (SiO2 + various cementing minerals)
Amygdaloidal Basalt
Amygdaloidal Basalt (with secondary mineral infilling)
Gneiss
Gneiss
Gneiss
Gneiss (High-grade metamorphic rock)
Granite Pebble (Weathered)
Phaneritic Felsic Igneous Rock
Banded Gneiss
Gneiss (Metamorphic Rock)
Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
Cobaltian Calcite
Cobalt-bearing Calcite (Ca,Co)CO3
Amygdaloidal Basalt
Amygdaloidal Mafic Volcanic Rock
Magnetite Sand (Black Sand)
Magnetite (Fe3O4)
Sandstone
Arenite (SiO2 based)
Quartz Pebble
Silicon Dioxide (SiO2)
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Malachite and Azurite on Gossan (Ironstone Matrix)
Cu2CO3(OH)2 (Malachite) on FeO(OH)·nH2O (Limonite/Gossan)
Fluorite
Calcium fluoride (CaF2)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Vesuvianite (Idocrase)
Ca19(Al, Mg, Fe)13(SiO4)10(Si2O7)4(OH, F, O)10
Bornite
Bornite (Cu5FeS4)
Granodiorite
Granodiorite (Intermediate intrusive igneous rock)
Sandstone with Magnetite and Iron Staining
Clastic Sedimentary Rock (contains Fe3O4 and Limonite/Hematite)
Mixed Mineral Specimens
Mixed Silicates, Oxides, and Phosphates (SiO₂, Ca₅(PO₄)₃(F,Cl,OH), Na₈Al₆Si₆O₂₄Cl₂, etc.)