Obsidian
Obsidian (Volcanic Glass)
Category
Browse mineral like (anthropogenic) specimens identified by the Rock Identifier community.
Obsidian
Obsidian (Volcanic Glass)
Orange Calcite with Siderite/Iron Oxide Coating
Calcium Carbonate (CaCO3)
Greenschist
Greenschist (containing Chlorite, Actinolite, and Epidote)
Sandstone
Arenite (composed primarily of SiO2)
Hematite (Botryoidal)
Hematite (Fe2O3)
Quartz Pebble
Silicon Dioxide (SiO2)
Blue Quartz
Silicon Dioxide (SiO2) with fibrous inclusions (such as tourmaline, magnesio-riebbeckite, or crocidolite)
K-Feldspar (Potassium Feldspar / Pink Feldspar)
KAlSi3O8 (Potassium Aluminum Silicate)
Fossil Snail
Gastropoda (fossilized)
Ruby in Fuchsite
Corundum (Al2O3) in Chrome-Mica (KAl2(AlSi3O10)(OH)2)
Quartz Vein in Host Rock
Quartz (SiO2) in metamorphic host rock (likely schist or phyllite)
Epidote
Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Basalt with Calcite Veins
Extrusive Igneous Rock
Granite
Felsic intrusive igneous rock
Basalt with Olivine and Scoria
Extrusive Igneous Rock
Granite Pegmatite
Pegmatite (Fulgite / Felsic Intrusive Rock)
Basalt with Quartz Veins
Aphanitic Mafic Igneous Rock (primarily Plagioclase and Pyroxene) with SiO2 inclusions
Sandstone (Ferruginous)
Ferruginous Sandstone (SiO2 with Fe2O3)
Green Schist
Greenschist (composed of Chlorite, Actinolite, and Epidote)
Clear Quartz Crystal
Silicon Dioxide (SiO2), Quartz
Amazonite (microcline feldspar)
K(AlSi3O8) - Potassium Aluminum Silicate
Petrified Wood
Silicified Wood (SiO2)
Sandstone (Red Sandstone)
Arenite
Chert (Flint)
Silicon Dioxide (SiO2)
Chalcedony Agate / Carnelian nodules in Matrix
SiO2 (Silicon Dioxide) with iron oxide inclusions
Vein-filled Sedimentary Rock
Silicified sedimentary rock with quartz/calcite vein
Selenite
Gypsum (CaSO4·2H2O)
Golden Calcite
Calcium Carbonate (CaCO3)
Limonite with Quartz (Gossan)
Hydrated iron(III) oxide-hydroxide mixture (FeO(OH)·nH2O) with Silicon Dioxide (SiO2)
Biotite Schist
Schist (Biotite-dominated)
Milky Quartz with Iron Oxide Weathering
Silicon Dioxide (SiO2) with Goethite/Limonite coatings
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Chrysoberyl (Cyclic Twin)
Beryllium Aluminum Oxide (BeAl2O4)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Limonite Sandstone
Ferruginous Sandstone (Hydrated Iron Oxide)
Botryoidal Chalcedony
Silicon Dioxide (SiO2)
Obsidian
Obsidian (Volcanic Glass)
Petrified Wood
Silicified Wood (SiO2)
Sandstone (with Concretion)
Arenite / Quartzose Sandstone
Generic Rock Fragment
Rock Fragment
Apatite
Fluorapatite (Ca5(PO4)3F)