Basalt Pebble
Basalt (Mafic Extrusive Igneous Rock)
Category
Browse mineral like byproduct (often mistaken for igneous rock or meteorite) specimens identified by the Rock Identifier community.
Basalt Pebble
Basalt (Mafic Extrusive Igneous Rock)
Obsidian
Obsidian (Volcanic Glass, complex silicate)
Granitic Gneiss
Gneiss (containing Potassium Feldspar and Quartz)
Sandstone
Sandstone (clastic sedimentary rock)
Sandstone (Ferruginous)
Clastic Sedimentary Rock (Litharenite)
Demitasse Granite (Diorite-Granite transition)
Intermediate Plutonic Rock (Granodiorite/Diorite mix)
Sandstone
Arenite (Clastic Sedimentary Rock)
Granite
Intrusive Felsic Igneous Rock
Orange Calcite
Calcium Carbonate (CaCO3)
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Granite
Granite (Mainly Quartz, Feldspar, and Mica)
Clear Quartz Crystal
Quartz (Silicon Dioxide, SiO2)
Scoria (Lava Rock)
Scoria (Vesicular Basalt)
Aquamarine
Beryllium aluminum silicate (Be3Al2Si6O18)
Obsidian
Volcanic glass (high silica volcanic rock)
Quartz (in a rock matrix)
Quartz (SiO2)
Pyrite
Iron Sulfide (FeS2)
Pumice
Pumice (volcanic glass formed of highly vesicular rough textured rock)
Copper Ore with Chrysocolla and Azurite
Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla) / Cu3(CO3)2(OH)2 (Azurite)
Sandstone with Magnetite and Iron Staining
Clastic Sedimentary Rock (contains Fe3O4 and Limonite/Hematite)
Eclogite
Eclogite (Omphacite-Garnet rock)
Basalt
Mafic Volcanic Rock (Primarily Plagioclase feldspar and Pyroxene)
Pumice
Vesicular volcanic glass (primarily SiO2)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Quartz Pebble
Silicon Dioxide (SiO2)
Flower Agate
Chalcedony (Silicon Dioxide, SiO2) with Opaque Spherulitic Inclusions
Granite
Granite (a broadly defined plutonic igneous rock, often more specifically classified as quartz monzonite or granodiorite based on precise mineral percentages)
Milky Quartz (with Iron Oxide staining)
Silicon Dioxide (SiO2)
Biotite Schist
Biotite Schist
Sandstone
Arenite (primarily SiO2)
Granite
Granite (a felsic intrusive igneous rock composed primarily of quartz, feldspar, and mica)
Pumice
Vesicular volcanic glass (primarily Alumino-silicates)
Gneiss
Gneiss (High-grade metamorphic rock)
Purple Lepidolite with Quartz
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)
Vesicular Basalt with Amygdules
Amygdaloidal Basalt
Blue Moss Agate / Blue Chalcedony
Silicon Dioxide (SiO2)
Schist (Garnet-Mica Schist)
Garnet-Mica Schist
Magnetite
Magnetite (Iron(II,III) oxide, Fe3O4)
Gneiss
Gneiss
Quartz Crystal (specifically a Double-Terminated variety)
Silicon Dioxide (SiO2) - Low Quartz
Sandstone
Clastic sedimentary rock (primarily SiO2)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)