Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Category
Not A Rock (Man Made Polymer)
Browse not a rock (man made polymer) specimens identified by the Rock Identifier community.
Jade (likely Nephrite Jade based on appearance)
Nephrite (a variety of actinolite, Ca2(Mg,Fe)5Si8O22(OH)2)
Mineral
Serpentine
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
metamorphic
Desert Rose (Baryte or Selenite variant)
Barium Sulfate (BaSO4) or Gypsum (CaSO4·2H2O) with Sand inclusions
mineral
Greywacke (likely)
Greywacke (a type of sandstone)
Sedimentary
Cullet Glass (Industrial Slag Glass)
Amorphous Silica (SiO2) with metallic oxide impurities
Man-made byproduct (often mistaken for Obsidian or Emerald)
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Garnet Schist
Almandine-Muscovite Schist
metamorphic
Yellow Quartzite (River Pebble)
Quartzite (SiO2)
metamorphic
Basalt
Basalt (Mafic volcanic rock)
igneous
Basalt with Granite Inclusions (Xenoliths)
Mafic igneous rock (Basalt) with Sialic minerals
igneous
Quartz Veined Basalt
Mafic Volcanic Rock with Microcrystalline Quartz (SiO2)
igneous
Geode with Quartz and possibly Jasper/Hematite
Quartz (SiO2) and Chalcedony (cryptocrystalline SiO2), possibly stained by iron oxides
Mineral/Sedimentary Geode
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Druzy Quartz on Chert/Chalcedony
Silicon Dioxide (SiO2)
mineral
Druzy Quartz on Chalcedony Matrix
Silicon Dioxide (SiO2)
mineral
Quartz Geode (likely within Limestone or Dolomite matrix)
Quartz (SiO₂)
Mineral within a Sedimentary Rock
Granodiorite
Phaneritic-textured Intrusive Granodiorite
igneous
Basalt
Basalt (Mafic volcanic rock)
igneous
Amber-bearing Coal/Sedimentary Rock
Bituminous coal or carbonaceous siltstone with Fossilized Tree Resin (C10H16O)
sedimentary
Gneiss
High-grade regional metamorphic rock (Foliated)
metamorphic
Basalt
Basalt
igneous
Shale (Beach-worn)
Laminated Pelite (primarily clay minerals and quartz)
sedimentary
Quartzite (Yellow/Orange variety)
Quartzite (primarily SiO2)
metamorphic
Desert Varnish on Sandstone
Ferromanganese coating on Quartz Arenite
sedimentary
Basalt with Quartz/Quartzite Veins
Aphanitic Mafic Volcanic Rock with Siliceous Infillings
igneous
Basalt
Mafic volcanic rock (primarily plagioclase, pyroxene, and olivine)
Igneous
Basalt with Iron Oxidation (Lattice/Veined)
Mafic Volcanic Rock (principally Plagioclase and Pyroxene)
igneous
Sandstone
Arenite (primarily SiO2)
sedimentary
Pebble (likely Sandstone or Granitic Pebble)
Clastic Sediment (or specific rock type, e.g., Arenite, Granitoid Pebble)
Rock (likely Sedimentary)
Basalt
Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)
Igneous
Sandstone (lithic wacke)
Arenite / Lithic Wacke (mostly SiO2 with rock fragments)
sedimentary
Porphyritic Basalt
Porphyritic Basalt (with Plagioclase phenocrysts)
igneous
Porphyritic Basalt (with Pyrolusite or Iron-oxide staining)
Porphyritic Basalt (Mafic Extrusive)
igneous
Sandstone
Arenite (SiO2 based with various mineral cements)
sedimentary
Glazed Ceramic Tile
Fused Silicate-Clay composite
Synthetic (Man-made material mimicking natural stone)
Druzy Quartz on Chert/Siltstone
Silicon Dioxide (SiO2) on Microcrystalline Silica/Siltstone matrix
sedimentary
Unidentified Rock Fragment
Unknown
Rock
Dyed Quartzite
Metamorphosed Quartz (SiO2) with synthetic pigment
metamorphic
Granite
Plutonic felsic rock (Quartz, Feldspar, Mica)
igneous
Slate
Foliated Metamorphic Rock (Mainly composed of Quartz, Illite, Chlorite)
metamorphic
Basalt with Quartz/Calcite Veins
Amygdaloidal Basalt (SiO2 or CaCO3 inclusions)
igneous