Gneiss (specifically Biotite Gneiss)
Gneiss (high-grade metamorphic rock primarily composed of Silicates)
Category
Browse mineral like byproduct specimens identified by the Rock Identifier community.
Gneiss (specifically Biotite Gneiss)
Gneiss (high-grade metamorphic rock primarily composed of Silicates)
Petrified Wood
Silicified Wood (primarily SiO₂ / Silicon Dioxide)
Specular Hematite
Specularite (Iron Oxide, Fe2O3)
Muscovite Mica
Muscovite - KAl2(AlSi3O10)(OH)2
Dendritic Opal
Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
Obsidian
Volcanic glass (Mainly SiO2)
Chert (White Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Asphalt (Bituminous Concrete)
Bituminous mix / Anthropogenic conglomerate
Travertine (Calcareous Tufa)
Calcium Carbonate (CaCO3)
Red Vanadinite on Matrix
Vanadinite (Pb5(VO4)3Cl)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Crushed Stone (Gravel/Aggregates)
Crushed rock aggregate (varied composition including Granite, Limestone, and Quartz)
Quartz (Milky/Smoky variety)
Silicon Dioxide (SiO2)
Muscovite Mica (likely on Quartz/Feldspar)
Muscovite - KAl2(AlSi3O10)(OH)2
Blue-dyed Quartz Druzy
Silicon Dioxide (SiO2) with artificial pigment
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals like Antigorite, Lizardite, and Chrysotile)
Serpentinite
Serpentinite (composed primarily of serpentine group minerals like lizardite, antigorite, and chrysotile)
Sandstone (with Liesegang rings or Oxidation)
Arenite (primarily Quartz SiO2 with Iron Oxide Fe2O3 staining)
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 cement)
Amethyst and Peridot
Amethyst (SiO2 with iron impurities) and Peridot ((Mg, Fe)2SiO4)
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals, Mg3Si2O5(OH)4)
Pink Granite
Phaneritic plutonic rock (dominated by Alkali Feldspar)
Granite
Granite (Mainly Quartz, Feldspar, and Mica)
Obsidian
Volcanic glass (SiO2 - Silicon dioxide predominant composition)
Obsidian (Black Obsidian)
Obsidian (Volcanic Glass)
Obsidian
Volcanic glass (high silica volcanic rock)
Granitic Pegmatite
Granite Pegmatite (typically containing Quartz SiO2, Feldspar KAlSi3O8, and Muscovite)
Sandstone (Quartzose Sandstone)
Clastic sedimentary rock (primarily SiO2)
Concretion (Sandstone)
Carbonate-cemented Sandstone Concretion
Quartzite with inclusions
Metamorphic Rock (Mainly SiO2)
Quartz (Rock Crystal)
Quartz (SiO₂ - Silicon Dioxide)
Smoky Quartz (Chlorite Inclusions)
Silicon Dioxide (SiO2) with trace Aluminum and Natural Irradiation
Moss Agate
Cryptocrystalline Quartz (SiO2 with Manganese or Iron Oxide inclusions)
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Schist
Mica Schist (primarily consisting of muscovite KAl2(AlSi3O10)(OH)2 or biotite K(Mg,Fe)3(AlSi3O10)(OH)2)
Oyster Shell (Aragonite/Calcite)
Calcium Carbonate (CaCO3)
Milky Quartz
Silicon Dioxide (SiO2)
Chert Nodule (Fossiliferous Chert)
Microcrystalline Quartz (SiO2)
Vesicular Basalt (Scoria)
Basalt (Extrusive Igneous Rock)
Blue Apatite
Apatite (Ca5(PO4)3(F,Cl,OH))
Greenschist / Migmatite
Regional Metamorphic Complex (Facies: Greenschist to Amphibolite)