Banded Gneiss
Gneiss (pronounced 'nice')
Category
Browse mineral (biogenic) specimens identified by the Rock Identifier community.
Banded Gneiss
Gneiss (pronounced 'nice')
Limonite (Ironstone)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Limonite Sandstone
Ferruginous Sandstone (Hydrated Iron Oxide)
Epidote
{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Epidote
Epidote ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))
Limonite (Yellow Ochre)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Limonite
Limonite (Hydrous iron oxides, predominantly Goethite FeO(OH)·nH2O)
Amygdaloidal Basalt with Secondary Minerals
Basalt containing secondary mineralization (likely Chlorite, Celadonite, or Zeolites)
Epidote
Epidote (Ca2(Al2,Fe3+)AlSi3O12(OH))
Magnetite
Magnetite (Fe3O4)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Greisen
Greisen
Greisen (Quartz-Muscovite-Turretine Rock)
Greisen
Rainbow Fluorite
Fluorite (Calcium Fluoride, CaF2)
Vanadinite
Lead Chlorovanadate, Pb5(VO4)3Cl
Nickel coin (U.S. currency)
Cupronickel (75% Copper, 25% Nickel alloy)
Boxwork Siderite or Sepatarian Nodule Weathering
Siderite (FeCO3) with secondary mineralization or Boxwork Geode fragment
Granite
Granite (Felsic Plutonic Rock)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Fluorite with Quartz coating
Calcium Fluoride (CaF2) with Silicon Dioxide (SiO2)
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)
Granite
Granite (Felsic Intrusive Igneous Rock)
Limonite/Goethite Nodule
Iron Oxyhydroxide (primarily FeO(OH)·nH2O)
Bauxite
Bauxite (Al(OH)3 mixed with Fe2O3 and clay minerals)
Limonite (Yellow Ochre)
Hydrated iron(III) oxide-hydroxides (FeO(OH)·nH2O)
Limonite (Iron Ore)
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)
Sandstone (Ferruginous)
Arenite (Fe2O3 staining)
Note regarding baguette production (not a rock)
Digital text image - Somali language
Diorite (River Rock/Cobble)
Intermediate Plutonic Igneous Rock (Diorite)
Gneiss
Gneiss (High-grade regional metamorphic rock)
Diorite
Phaneritic intermediate plutonic rock
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)
Gneiss
Gneiss