Black Obsidian
Obsidian (Volcanic glass), 70–75% SiO2
Category
Browse igneous rock specimens identified by the Rock Identifier community.
Black Obsidian
Obsidian (Volcanic glass), 70–75% SiO2
Aquamarine
Beryl (Be3Al2Si6O18 with trace Fe2+)
Dalmatian Jasper
Peralkaline rhyolite
Obsidian / Volcanic Glass
Obsidian (principally SiO2, usually 70% or more)
Obsidian (Black)
Obsidian (approx. 70–75% SiO2)
Peach Moonstone
Potassium Aluminum Silicate (KAlSi3O8)
Orange Quartz
Silicon Dioxide (SiO2) with Iron Oxide inclusions
White Topaz
Aluminum Silicate Fluoride Hydroxide; Al2SiO4(F,OH)2
Granite
Granite (a felsic intrusive igneous rock composed primarily of quartz, feldspar, and mica)
Basalt River Stone
Basalt
Red Granite
Phaneritic Felsic Intrusive Igneous Rock (primarily K-feldspar, Quartz, and Biotite)
Pink Granite
Phaneritic Felsic Intrusive Igneous Rock (composed of Quartz, Alkali Feldspar, and Plagioclase)
Granite
Phaneritic Intrusive Igneous Rock (primarily composed of SiO2, Al2O3, K2O, Na2O)
Pink Granite
Granite (Phaneritic igneous rock composed mainly of quartz, alkali feldspar, and plagioclase)
Pink Granite
Phaneritic Felsic Igneous Rock (composed primarily of K-Feldspar, Quartz, and Plagioclase)
Granite Pebble
Granite (Phaneritic intrusive igneous rock consisting of Quartz, Alkali Feldspar, and Plagioclase)
Basalt (River Pebble)
Basalt (dominated by Plagioclase Feldspar and Pyroxene)
Granodiorite
Granodiorite (NaAlSi3O8 to CaAl2Si2O8 / SiO2)
Granitic Sand
Detrital sediment (predominantly Quartz, Feldspar, and Mica)
Obsidian
Volcanic Glass (Amorphous Silica)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Amethyst
Crystalline Quartz (SiO2) with iron impurities
Granite
Granite (phaneritic intrusive igneous rock consisting mainly of quartz, alkali feldspar, and plagioclase)
Obsidian
Obsidian (volcanic glass), amorphous SiO2 + impurities
Que Sera Stone (Llanite)
Rhyolite Porphyry with Blue Quartz and Feldspar
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite inclusions
Milk Quartz (White) and Yellow Aventurine (Yellow)
Silicon Dioxide (SiO2)
Tree Agate (Dendritic Agate/Quartz)
Silicon Dioxide (SiO2) with trace Manganese or Iron oxide inclusions
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Porphyry (specifically Porphyritic Basalt or Andesite)
Porphyritic extrusive igneous rock (Mg,Fe)2SiO4 (Olivine inclusions/Plagioclase Feldspar)
Rose Quartz
Silicon Dioxide with trace inclusions of dumortierite or titanium (SiO2)
Larvikite
Monzonite (intermediate intrusive igneous rock containing plagioclase, alkali feldspar, augite, and biotite)
Granite
Granite (phaneritic intrusive igneous rock consisting mainly of quartz, alkali feldspar, and plagioclase)
Granite (Pink/Red variety)
Phaneritic Felsic Intrusive Igneous Rock (composed primarily of Quartz, K-Feldspar, and Plagioclase)
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Dalmatian Stone
Peralkaline Quartz-Feldspar Rock with Arfvedsonite
Obsidian
Volcanic Glass (SiO2)
Agate
Silicon Dioxide (SiO2) - Chalcedony variant
Amphibolite
Amphibolite
Ocean Jasper
Orbicular Jasper (SiO2)
Aquamarine
Beryl (Be3Al2Si6O18 with iron impurities)
Flower Agate
Chalcedony (Silicon Dioxide, SiO2) with Opaque Spherulitic Inclusions