Sandstone
Sedimentary Rock (Quartz Arenite)
Category
Browse metamorphic rock (for nephrite and some jadeite); mineral (for jadeite) specimens identified by the Rock Identifier community.
Sandstone
Sedimentary Rock (Quartz Arenite)
Crinoid Stem Fossil
Crinoid Columnal (Phylum Echinodermata)
Labradorite (Feldspar)
Labradorite: (Ca,Na)(Al,Si)4O8
Fossilized Shark Tooth
Chondrichthyes (class) fossilized tooth
Garnet (likely Almandine, Pyrope, or a blend)
Garnet group minerals: X3Y2(SiO4)3, where X and Y represent various metal ions (e.g., Almandine: Fe3Al2(SiO4)3, Pyrope: Mg3Al2(SiO4)3)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of Titanium, Iron, or Manganese
Emerald
Beryl (Be₃Al₂(SiO₃)₆) with Chromium or Vanadium impurities
Obsidian
Volcanic Glass (Amorphous Silica)
Tumbled limestone or calcite-rich stone
Limestone, predominantly calcite (CaCO₃); exact identification is uncertain from the photograph
Sandstone Beach Pebble
Clastic Sandstone (SiO2 - Quartz-dominant)
Painted River Rock
Artificially Coated Sedimentary Rock
Biotite on Quartz
Biotite Mica (K(Mg,Fe)3AlSi3O10(F,OH)2)
Mixed Rock Collection (Pebbles and Stones)
Various geological specimens
Chrysocolla on Matrix
Hydrated copper silicates ((Cu,Al)2H2Si2O5(OH)4·nH2O)
Fossilized ammonite (likely weathered ammonite cross-section)
Ammonoidea; commonly Jurassic–Cretaceous ammonite fossils replaced by calcite or aragonite
Chert (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
Greenstone
Greenschist (Greened Metabasalt)
Magnetite (Iron Ore)
Magnetite (Fe3O4)
Bornite
Cu5FeS4
Chert (concretionary/nodular variant)
Microcrystalline Quartz (SiO2) with possible fossil or mineral inclusions
Gneiss
Gneiss (Metamorphic Rock)
Amethyst (Tumbled)
Amethyst (SiO2 with iron impurities)
Almandine Garnet in Schist
Almandine, Fe3Al2(SiO4)3
White Coral
Corallium rubrum (biocarbonate calcium) / CaCO3
Gneiss
High-grade regional metamorphic rock (Foliated)
Black Tourmaline
Schorl (Na(Fe2+)_{3}Al_{6} (BO_{3})_{3} (Si_{6}O_{18})(OH)_{4})
Geode (Unopened)
Siliceous Concretion / Geode
Greenstone / Basalt
Metabasalt (often containing Chlorite, Epidote, and Actinolite)
Muscovite Mica
Muscovite: KAl2(AlSi3O10)(OH)2
Epidote
{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Desert Rose
Selenite Rose (Gypsum: CaSO4·2H2O)
Quartz Vein / Milky Quartz
Silicon Dioxide (SiO2)
Ironstone with Pyrite
Ferruginous Sandstone (Fe2O3) with minor Sulfide minerals (FeS2)
Sandstone with Iron Oxide (Limonite/Hematite)
Ferruginous Sandstone (SiO2 with FeO(OH)·nH2O)
Arsenopyrite in Quartz Matrix
Arsenopyrite (FeAsS) with Quartz (SiO2)
Garnet (likely Almandine or a blend)
Garnet group: X3Y2(SiO4)3, where X can be Ca, Mg, Fe2+, Mn2+ and Y can be Al, Fe3+, Cr3+. Given the dark, somewhat reddish-brown appearance in the image, it's likely Almandine (Fe3Al2(SiO4)3) or a mix with other iron-rich garnets.
Biotite Schist
Biotite Schist
Garnet-bearing Schist
Almandine Garnet [Fe3Al2(SiO4)3] in Micaceous Schist
Spessartine Garnet in Quartz/Feldspar Pegmatite
Spessartine (Mn3Al2(SiO4)3) in Quartz (SiO2) and Feldspar
Agate (Thunderegg segment)
Silicon dioxide (SiO2) - Microcrystalline Quartz/Chalcedony
Granitic Pegmatite
Pegmatite (Quartz: SiO2, Feldspar: KAlSi3O8, Mica: KAl2(AlSi3O10)(OH)2)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Extrusive)