Gneiss
Gneiss (high-grade metamorphic rock typically composed of quartz, feldspar, and mica)
metamorphic
Category
Mineral Based Composite
Browse mineral based composite specimens identified by the Rock Identifier community.
Granite
Granite (Phaneritic igneous rock)
igneous
Granite
Granite (Silicic Plutonic Rock)
igneous
Granodiorite
Granodiorite (containing quartz, plagioclase, and biotite/hornblende)
igneous
Muscovite Mica (on Quartz Matrix)
Muscovite - KAl2(AlSi3O10)(OH)2
mineral
Fire Agate
SiO2 (Silicon Dioxide with Iron Oxide inclusions)
mineral
Rough Emerald (Beryl)
Emerald (Be3Al2(SiO3)6 with Cr/V impurities)
mineral
Fuchsite
Chromium-rich Muscovite (KAl2(AlSi3O10)(OH,F)2 with Cr replacements)
mineral
Biotite (Black Mica)
Biotite - K(Mg,Fe)3AlSi3O10(F,OH)2
mineral
Mica (Muscovite)
Muscovite (KAl2(AlSi3O10)(OH)2)
mineral
Dendritic Jasper
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
sedimentary
Granite
Granite (a common name for a felsic intrusive igneous rock)
Igneous Rock
Vesicular Basalt (Scoria)
Extrusive Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
igneous
Granite
Phaneritic Felsic Igneous Rock
igneous
Granite
Phaneritic Felsic Igneous Rock
igneous
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone (likely Siltstone variety)
Arenite / Siltstone (primary mineral SiO2)
sedimentary
Sandstone with Manganese Dendrites/Oxide coatings
Arenite with Pyrolusite and Romanechite (MnO2)
sedimentary
Serpentine
Antigorite, Lizardite, or Chrysotile (Mg, Fe)3Si2O5(OH)4
metamorphic
Coquina / Shelly Limestone
Coquina (calcium carbonate, CaCO3)
sedimentary
Granite
Granite (Phaneritic Acid Igneous Rock)
igneous
Sandstone (Glacial Cobble)
Arenite / Sedimentary Rock (primarily SiO2)
sedimentary
Quartz (specifically Milky Quartz or Quartzite)
Silicon Dioxide (SiO2)
mineral
Labradorite
Feldspar (variety of Anorthite), (Ca,Na)(Al,Si)4O8
mineral
Moss Agate
Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite
mineral
Mica Schist
Mica Schist (primarily Muscovite and Biotite composition)
metamorphic
Sandstone (Quartzose type)
Arenite (primarily SiO2)
sedimentary
Granite
Granite (composed primarily of Quartz SiO2, Alkali Feldspar KAlSi3O8, and Plagioclase)
igneous
Granite
Granite
igneous
Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Mica (Biotite and Muscovite) in Matrix
Potassium aluminum silicate with iron/magnesium (KAl2(AlSi3O10)(F,OH)2 / K(Mg,Fe)3AlSi3O10(F,OH)2)
igneous
Red Mudstone (Siltstone)
Lutite (primarily Quartz and Clay minerals with Hematite)
sedimentary
Gneiss
Gneiss
metamorphic
Garnet-Bearing Gneiss
Almandine-Garnet Gneiss
metamorphic
Graphite
Graphite (Chemical Formula: C)
Mineral (Native Element)
Porphyritic Basalt (Amygdaloidal)
Porphyritic Mafic Volcanic Rock (Amygdaloidal Basalt)
igneous
Basalt
Extrusive mafic igneous rock
igneous
Granite
Granite (Mainly Quartz, Feldspar, and Mica)
igneous
Flower Agate (Cherry Blossom Agate)
Chalcedony (SiO2) with Opaque Inclusions
mineral
Mica Schist
Mica Schist (primarily Muscovite or Biotite sheet silicates)
metamorphic
Dalmatian Jasper (Dalmatian Stone)
Dalmatian Stone (primarily Feldspar, Quartz, and Arfvedsonite/Tourmaline)
igneous
Muscovite Mica (in Quartz matrix)
Potassium aluminum silicate hydroxide fluoride (KAl2(AlSi3O10)(F,OH)2)
mineral