Gneiss (Metamorphic Rock)
Gneiss
metamorphic
Category
Mineral (Biogenic)
Browse mineral (biogenic) specimens identified by the Rock Identifier community.
Kimberlite with Diamond
Kimberlite (Porphyritic Peridotite)
igneous
Diorite (River Pebble)
Intermediate plutonic igneous rock
igneous
Pink Granite
Phaneritic plutonic rock (dominated by Alkali Feldspar)
igneous
Diorite (Polished Cobble)
Diorite (Intermediate intrusive igneous rock)
Igneous
River Cobble (Gneiss/Migmatite)
Gneissic Metamorphic Rock (composed mainly of Quartz, Feldspar, and Biotite)
metamorphic
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
Orange Calcite
Calcium Carbonate (CaCO3)
mineral
Granite
Granite (composed primarily of Quartz SiO2, Orthoclase KAlSi3O8, and Plagioclase NaAlSi3O8 to CaAl2Si2O8)
Igneous
River Quartzite Siltstone
Quartz-rich Meta-siltstone (SiO2 dominated)
metamorphic
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
Azurite
Azurite (Copper Carbonate Hydroxide), Cu3(CO3)2(OH)2
mineral
Sodalite
Sodalite (Sodium Aluminum Silicate Chloride), Na8(Al6Si6O24)Cl2
Mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Rhodochrosite
Manganese carbonate (MnCO3)
mineral
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
Granitic Pegmatite
Granite Pegmatite (principally KAlSi3O8, SiO2, and KAl2(AlSi3O10)(OH)2)
igneous
Rhodonite
Rhodonite (Manganese Silicate), (Mn,Fe,Mg,Ca)SiO3
mineral
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Slag
Anthropogenic Iron Silicate Glass
mineral
Jasper (specifically Polychrome or Desert Jasper)
Silicon Dioxide (SiO2) with iron oxide and other mineral impurities
sedimentary (chemical/biological origin)
Yellow Beryl (Heliodor)
Beryllium aluminum silicate (Be3Al2Si6O18)
mineral
Granite
Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)
igneous
Mica Schist
Mica Schist (KAl2(AlSi3O10)(OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)
metamorphic
Chrysocolla in Matrix
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4' nH2O on Quartz/Feldspar matrix
mineral