River Cobble (Gneiss/Migmatite)
Gneissic Metamorphic Rock (composed mainly of Quartz, Feldspar, and Biotite)
metamorphic
Category
Mineral Group
Browse mineral group specimens identified by the Rock Identifier community.
River Quartzite Siltstone
Quartz-rich Meta-siltstone (SiO2 dominated)
metamorphic
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Basalt with Quartz/Calcite Vein
Basalt (Mafic Volcanic Rock with secondary mineralization)
igneous
Milky Quartz (Water-worn Pebble)
Silicon Dioxide (SiO2)
mineral
Limonite and Goethite encrusted Quartz (Iron-stained Gossan)
FeO(OH)·nH2O (Limonite) / FeO(OH) (Goethite) on SiO2 (Quartz)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Quartz Vein in Sedimentary Matrix
Silicon Dioxide (SiO2) with host rock
mineral
Specular Hematite (Iron Ore)
Iron(III) oxide (Fe2O3)
mineral
Diamond (in a cluster setting)
Crystallized Carbon (C)
mineral
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide inclusions
mineral
Brachiopod Fossil in Limestone
Phylum Brachiopoda (likely Order Spiriferida), CaCO3 (Calcite)
sedimentary
Snowflake Obsidian
Volcanic glass containing Spherulitic Cristobalite (SiO2)
igneous
Quartzite Pebble
Quartzite (primarily SiO2)
metamorphic
Olivine in Basalt (Peridot)
Magnesium Iron Silicate (Mg, Fe)2SiO4 in Vesicular Basalt
igneous
Granodiorite
Granodiorite
igneous
Sandstone
Arenite (primarily SiO2)
sedimentary
Quartzite with inclusions
Quartzite (primarily SiO2)
metamorphic
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
metamorphic
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Granodiorite
Granodiorite (containing Quartz, Plagioclase Feldspar, Biotite, and Hornblende)
igneous
Granitic Pegmatite
Granite Pegmatite (principally KAlSi3O8, SiO2, and KAl2(AlSi3O10)(OH)2)
igneous
Limonite and Goethite
Limonite (hydrated iron(III) oxide-hydroxide) and Goethite (α-FeO(OH))
mineral
Mica Schist
Mica Schist (primarily Muscovite or Biotite KAl2(AlSi3O10)(OH)2)
metamorphic
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Mica Schist
Mica Schist (KAl2(AlSi3O10)(OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)
metamorphic
Slag
Anthropogenic Iron Silicate Glass
mineral
Azurite
Azurite (Copper Carbonate Hydroxide), Cu3(CO3)2(OH)2
mineral
Sodalite
Sodalite (Sodium Aluminum Silicate Chloride), Na8(Al6Si6O24)Cl2
Mineral
Rhodonite
Rhodonite (Manganese Silicate), (Mn,Fe,Mg,Ca)SiO3
mineral
Granite (Dioritic or Hornblende-rich)
Phaneritic Plutonic Felsic to Intermediate Igneous Rock
igneous
Chrysocolla in Matrix
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4' nH2O on Quartz/Feldspar matrix
mineral
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
mineral
Tiffany Stone
Bertrandite (Be4Si2O7(OH)2) mixed with Fluorite (CaF2), Opal, and Chalcedony
mineral
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
mineral
Diamond
Native Carbon (C)
mineral
Diamond (Princess Cut)
Carbon (C)
mineral
Garnet
Almandine formula: Fe3Al2(SiO4)3
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Orange Calcite (Banded Calcite)
Calcium Carbonate (CaCO3)
mineral
Blue Sapphire
Corundum (Al2O3) with traces of Iron and Titanium
mineral