Banded Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Category
Mineral On Sedimentary Rock
Browse mineral on sedimentary rock specimens identified by the Rock Identifier community.
Sandstone (Red)
Arenite (primarily Quartz, SiO2, with Iron Oxide cement)
sedimentary
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Dark Igneous Rock (Likely Basalt or Diabase)
Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.
Igneous
Almandine Garnet in Schist Matrix
Almandine - Fe3Al2(SiO4)3
metamorphic
Septarian Nodule (Septarian Dragon Stone)
Septarian Concretion (CaCO3 + Al2Si2O5(OH)4)
sedimentary
Chert (Nodule)
Microcrystalline or Cryptocrystalline Silica (SiO2)
sedimentary
Sandstone (with Liesegang rings or joints)
Clastic Sedimentary Rock (primarily Quartz with Iron Oxide cement)
sedimentary
Carnelian
Carnelian (SiO2, Silicon Dioxide with Iron Oxide impurities)
mineral
Chert (Brecciated or Veined)
Silicon Dioxide (SiO2)
sedimentary
Chalcedony in Host Rock
Chalcedony (SiO2)
mineral
Sandstone Concretion
Clastic sedimentary rock (primarily Silica, SiO2, or Calcium Carbonate, CaCO3)
sedimentary
Garnet-Mica Schist
Garnetiferous Porphyroblastic Schist
metamorphic
Smoky Quartz and Biotite Schist
Quartz-Biotite Schist (SiO2 + K(Mg,Fe)3AlSi3O10(F,OH)2)
metamorphic
Magnetite (Iron Ore)
Magnetite (Fe3O4)
mineral
Gneiss
Gneiss (high-grade metamorphic rock typically composed of quartz, feldspar, and mica)
metamorphic
Sandstone or Mudstone
Sedimentary Rock (Sandstone/Mudstone)
sedimentary
Granite
Phaneritic plutonic rock (primarily Quartz, Feldspar, and Mica)
igneous
Mica Schist
Foliated Metamorphic Rock (rich in Muscovite or Biotite)
metamorphic
Red Sandstone (Old Red Sandstone Pebble)
Arenite with iron oxide (Fe2O3) cement
sedimentary
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Limonite (Iron Ore/Sandstone mixture)
Limonite (FeO(OH)·nH2O) often mixed with Goethite and sedimentary matrix
mineral
Conglomerate
Conglomerate
Sedimentary
Yellow Calcite
Calcium Carbonate (CaCO3)
mineral
Gneiss (specifically a Granitic Gneiss)
Gneiss (typically composed of Quartz, Feldspar, and Mica/Amphiboles)
metamorphic
Asphalt Chunk (with aggregate)
Bituminous concrete / Anthropogenic conglomerate
sedimentary (anthropogenic/man-made conglomerate)
Sandstone (Muddy/Silty Variety)
Arenite with high silt/clay content (clastic sedimentary rock)
sedimentary
Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
Gneiss
High-grade regional metamorphic rock (Foliated)
metamorphic
Quartz (likely a form of massive or vein quartz)
Quartz (SiO₂)
Mineral
Gneiss
Gneiss (a type of metamorphic rock)
Metamorphic Rock
Almandine Garnet in Matrix
Almandine (Fe3Al2(SiO4)3)
metamorphic
Jasper with Quartz Druzy
Silicon Dioxide (SiO2)
sedimentary
Quartz
Silicon Dioxide (SiO2)
Mineral
Gneiss
Metamorphic rock of high-grade regional metamorphism
metamorphic
Quartz Druze on Matrix
Silicon Dioxide (SiO2)
mineral
Red Sandstone
Clastic Terrigenous Sedimentary Rock (typically Hematitic Quartz Arenite or Arkose)
sedimentary
Agate and Amethyst (Quartz variants)
Silicon Dioxide (SiO2) - Microcrystalline Quartz and Crystalline Quartz
mineral
Liesegang Ring Siltstone
Siltstone with iron oxide Liesegang bands
sedimentary
Chert (Jasper/Agate variety)
Cryptocrystalline Quartz (SiO2)
sedimentary
Porphyritic Basalt (Chinese Flower Stone / Chrysanthemum Stone basalt variety)
Porphyritic Basalt containing Plagioclase Feldspar phenocrysts
igneous
Blue Lace Agate
Cryptocrystalline Quartz (SiO2) with trace minerals
sedimentary