Basalt
Basalt (Mafic volcanic rock)
Category
Browse igneous and mineral specimens identified by the Rock Identifier community.
Basalt
Basalt (Mafic volcanic rock)
Basalt
Aphanitic mafic volcanic rock (primarily plagioclase feldspar and pyroxene)
Basalt
Basalt (primarily composed of Plagioclase Feldspar and Pyroxene)
Granite
Phaneritic Igneous Rock (composed primarily of Quartz, Feldspar, and Mica)
Granite
Granite (Phaneritic intrusion / SiO2 + KAlSi3O8 + NaAlSi3O8)
Granite
Granite (Mainly Quartz, Feldspar, and Mica)
Labradorite
(Ca,Na)(Al,Si)4O8
Clear Quartz (Rock Crystal)
Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Granite (River-worn Cobble)
Phaneritic Felsic Igneous Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide - SiO2)
Granite
Phaneritic Plutonic Felsic Rock
Greenstone
Protolith of basalt/gabbro (chlorite-epidote metamorphic facies)
Black Tourmaline
Schorl (NaFe2+3Al6(BO3)3Si6O18(OH)4)
Magnetite (Lodestone)
Magnetite (Fe3O4)
Diorite (Salt and Pepper Rock)
Diorite
Pink Granite
Phaneritic Plutonic Rock (Felsic)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Obsidian
Obsidian (Amorphous volcanic glass)
Peridotite
Peridotite (Ultramafic Rock)
Obsidian
Obsidian (Volcanic Glass)
Diorite
Diorite
Black Obsidian with white veins
Volcanic Glass (70–75% SiO2)
Quartz with Mica and Feldspar
Granitic Pegmatite Fragment (SiO2 + KAlSi3O8 + KAl2(AlSi3O10)(OH)2)
Black Obsidian
Obsidian (Volcanic Glass)
Obsidian
Volcanic Glass (predominantly SiO2)
Granite Pebble
Felsic Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
Granite
Granite (Plutonic Felsic Igneous Rock)
Granite
Granite (Mainly Quartz SiO2, Alkali Feldspar (K,Na)AlSi3O8, and Plagioclase Feldspar)
Greenschist
Greenschist (Chlorite Schist)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Gneiss with Quartz/Feldspar Vein
Quartz-Feldspathic Gneiss
Basalt with Red Inclusions
Aphanitic Mafic Igneous Rock (likely Basalt)
Gabbro
Gabbro (Mg,Fe)2Si2O6 and CaAl2Si2O8
Basalt with Quartz Infill
Basalt (Mafic Extrusive Volcanic Rock)
Olivine in Basalt (Peridot)
Magnesium Iron Silicate (Mg, Fe)2SiO4 in Vesicular Basalt
Granodiorite
Granodiorite
Granite
Phaneritic Intrusive Igneous Rock (Granite)
Serpentine (Serpentinite)
Hydrous magnesium iron silicate, (Mg,Fe)3Si2O5(OH)4
Rose Quartz and Clear Quartz beads
Quartz (Silicon Dioxide, SiO2)