Basalt
Basalt (Mafic Extrusive Igneous Rock)
Category
Browse sedimentary (base), then artificial specimens identified by the Rock Identifier community.
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Amygdaloidal Basalt
Amygdaloidal Basalt (Mafic Volcanic Rock)
Diorite (Salt and Pepper Rock)
Diorite
Diorite
Diorite (Intermediate intrusive igneous rock)
Vesicular Basalt
Amygdaloidal Basalt (Mafic extrusive volcanic rock)
Quartzite
Quartzite (primarily SiO2)
Granodiorite
Granodiorite (phaneritic intrusive igneous rock)
Basalt
Mafic Extrusive Igneous Rock
Diorite
Diorite
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Basalt
Extrusive Mafic Igneous Rock
Ferro-Manganese Slag
Vitreous Silicate Slag
Granite
Phaneritic Plutonic Rock (primarily Quartz, Feldspar, and Mica)
Basalt (River Cobble)
Basalt (Mafic volcanic rock)
Basalt (River Pebble)
Basalt (Aphanitic Mafic Volcanic Rock)
Basalt
Basalt (Mafic volcanic rock)
Ferruginous Quartz (Iron-stained Quartz)
Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3)
Basalt with Quartz Veins
Amygdaloidal Basalt (matrix) with Crystalline SiO2 (veins)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Basalt
Basalt (Mafic volcanic rock)
Granitic Gneiss
Gneiss (Polymetamorphic Granitic Gneiss)
Granite
Phaneritic plutonic rock (composed of Quartz, Feldspar, and Mica/Amphibole)
Diorite
Intrusive Igneous Diorite (intermediate composition)
Gabbro
Gabbro (composed mainly of calcium-rich plagioclase feldspar and pyroxene)
Granite
Granite (Felsic Plutonic Rock)
Quartzite
Quartzite
Quartzite
Quartzite (SiO2)
Amethyst Quartz (Amethyst Geode)
Silicon Dioxide (SiO2) with iron impurities
Basalt
Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Basalt Pebble
Basalt (Aphanitic Mafic Volcanic Rock)
Basalt
Basalt
Basalt with Quartz/Epidote Vein
Mafic volcanic rock (formula primarily (Mg, Fe)2SiO4 and CaAl2Si2O8)
Basalt (Porphyritic Basalt)
Porphyritic Basalt (Mafic volcanic rock)
Granite Cobble
Felsic intrusive igneous rock (composition: SiO₂ with KAlSi₃O₈, NaAlSi₃O₈, and CaAl₂Si₂O₈)
Granite
Granite (Phaneritic Quartz-Feldspar Felsic Rock)
Diorite (Salt and Pepper Rock)
Phaneritic Plutonic Diorite; chemical composition roughly 52-63% silica (SiO2)
Basalt with Plagioclase Phenocrysts
Porphyritic Basalt
Anthracite Coal
Anthracite (high-rank coal / Carbon)
Ferruginous Quartz
Silicon Dioxide (SiO2) with Hematite/Goethite inclusions
Basalt
Basalt (Mafic volcanic rock)
Diorite (with Iron Staining)
Phaneritic Intermediate Igneous Rock