Obsidian
Volcanic glass (high silica volcanic rock)
Category
Browse igneous and mineral specimens identified by the Rock Identifier community.
Obsidian
Volcanic glass (high silica volcanic rock)
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Obsidian
Obsidian (principally SiO2 + MgO, Fe3O4)
Smoky Quartz and Orthoclase Feldspar
Granitic Pegmatite (SiO2 + KAlSi3O8)
Obsidian
Obsidian (Volcanic Glass, SiO2 dominated)
Graphic Granite
Graphic Granite (a variety of Pegmatite)
Granite
Granite (Silicic Plutonic Rock)
Granite
Granite (Felsic Plutonic Rock)
Granite Pebble
Felsic Intrusive Igneous Rock (composed of Quartz, Feldspar, and Mica)
Granite
Granite (Felsic Plutonic Rock)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Granite (Granitic Pegmatite/Porphyry)
Felsic intrusive igneous rock (Quartz, Feldspar, Mica composition)
Granite
Phaneritic Felsic Igneous Rock (Granite)
Basalt with Vesicle/Vug
Basalt (Aphanitic Mafic Igneous Rock)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Sunstone
Aventurine Feldspar ((Ca,Na)(Al,Si)4O8)
Clear Quartz
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Carnelian
SiO2 (Microcrystalline Quartz / Chalcedony)
Milky Quartz
Silicon Dioxide (SiO2)
Gold
Gold (Native Element); Au
Milky Quartz
Silicon Dioxide (SiO2)
Brown Agate
Silicon Dioxide (SiO2)
Yellow Quartz (Citrine or Iron-Stained Quartz)
Silicon Dioxide (SiO2)
White Quartz
Silicon Dioxide (SiO2)
Sodalite
Sodalite (Na8Al6Si6O24Cl2)
Moonstone (specifically White Moonstone/Adularia)
Potassium aluminum silicate ((K,Na)AlSi3O8)
Quartz (River Cobble)
Silicon Dioxide (SiO2)
Milky Quartz (with potential inclusion of feldspar)
Silicon Dioxide (SiO2)
Milky Quartz with Iron Staining
Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Carnelian
Carnelian (a variety of Chalcedony), SiO2 (Silicon Dioxide)
Sodalite
Sodalite, Na8(Al6Si6O24)Cl2
Blue Sapphire
Corundum (Al2O3 with trace amounts of iron and titanium)
Blue Lace Agate
Chalcedony (SiO2) with trace impurities
Muscovite (Mica)
Muscovite - KAl2(AlSi3O10)(OH)2
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese