Quartzite
Quartzite (primarily SiO2)
Category
Browse mineral description (anthropogenic material) specimens identified by the Rock Identifier community.
Quartzite
Quartzite (primarily SiO2)
Limonite (Ironstone)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Limonite Sandstone
Ferruginous Sandstone (Hydrated Iron Oxide)
Epidote
Epidote ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))
Epidote
{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Limonite
Limonite (Hydrous iron oxides, predominantly Goethite FeO(OH)·nH2O)
Amygdaloidal Basalt with Secondary Minerals
Basalt containing secondary mineralization (likely Chlorite, Celadonite, or Zeolites)
Limonite (Yellow Ochre)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Red Coral
Corallium rubrum (for precious red coral), although other species like Corallium japonicum and Paracorallium are also used.
Epidote
Epidote (Ca2(Al2,Fe3+)AlSi3O12(OH))
Magnetite
Magnetite (Fe3O4)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Vanadinite
Lead Chlorovanadate, Pb5(VO4)3Cl
Rainbow Fluorite
Fluorite (Calcium Fluoride, CaF2)
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
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Granite
Granite (Felsic Plutonic Rock)
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)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Limonite (Yellow Ochre)
Hydrated iron(III) oxide-hydroxides (FeO(OH)·nH2O)
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)
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
Arsenopyrite in Quartz Matrix
Arsenopyrite (FeAsS) with Quartz (SiO2)
Black Sand (Magnetite Sand)
Magnetite (Fe3O4)
Quartzite
Quartzite (SiO2)
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)