Obsidian
Volcanic Glass (SiO2)
Category
Browse igneous or sedimentary specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass (SiO2)
Glacial Cobble (likely Granitic or Gneissic)
Granite/Gneiss Glacial Erratic
Granite
Phaneritic plutonic rock (Quartz, Feldspar, Mica)
Porphyritic Basalt
Basalt with plagioclase phenocrysts
Lepidolite in Quartz (or Lepidolite Ore)
Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2) in Quartz (SiO2)
Basalt (Vesicular/Scoria)
Vesicular Basalt
Brown Antique Granite
Anorthosite (Technically a plutonic rock composed mainly of plagioclase feldspar)
Basalt with Garnet inclusions
Basalt containing Nesosilicate (Garnet Group, likely Almandine Fe3Al2Si3O12)
Porphyritic Rhyolite (Red)
Rhyolite (Porphyry)
Scoria
Vesicular Basaltic Andesite/Scoria
Obsidian (Apache Tear)
Amorphous Volcanic Glass (SiO2 + impurities)
Granite
Granite (Felsic Plutonic Rock)
Chondrite Meteorite
Ordinary Chondrite (S-type asteroid origin)
Basalt
Basalt
Bumble Bee Jasper
Volcanic Tuff (mixture of SiO2, CaCo3, S, and As2S3)
Granite
Granite (Felsic Plutonic Rock)
Porphyritic Andesite
Andesite (Intermediate Extrusive Volcanic Rock)
Obsidian
Volcanic glass (primary composition: SiO2)
Granodiorite Pebble
Granodiorite
Pumice
Pumice (Vesicular Rhyolite/Andesite)
Vesicular Basalt (or Porphyritic Scoria)
Vesicular Basalt
Basalt
Basalt
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Obsidian
Volcanic Glass (SiO2 rich)
Granite
Granite
Andesite Porphyry
Porphyritic Andesite
Basalt with Quartz Veins
Basalt (complex silicate) with Quartz (SiO2) intrusions
Basalt (Vesicular/Scoriaceous)
Extrusive Mafic Volcanic Rock (Primarily Plagioclase Feldspar and Pyroxene)
Granite Pebble
Granite (Phaneritic Quartz-Feldspar intrusive rock)
Orthoclase (Potassium) Feldspar in Quartz
KAlSi3O8 (Potassium Aluminum Silicate)
Basalt (River Pebble)
Basalt (Aphanitic Mafic Volcanic Rock)
Basalt
Basalt (predominantly Plagioclase Feldspar and Pyroxene)
Basalt with Quartz/Calcite Vein
Basalt (Mafic Volcanic Rock with secondary mineralization)
Indigo Gabbro
Gabbro (MaFIC intrusive rock)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Obsidian
Volcanic Glass (predominantly SiO2)
Granite
Granite (Felsic Plutonic Rock)
Basalt with Plagioclase Phenocrysts (Porphyritic Basalt)
Mafic volcanic rock (formula primarily (Mg, Fe)2SiO4 and CaAl2Si2O8)
Basalt (Water-worn pebble)
Basalt (Mafic Extrusive Rock)
Obsidian
Volcanic Glass (SiO2 + impurities)
Kimberlite
Kimberlite (Group I or II)
Basalt
Basalt (Mafic Extrusive)