Basalt
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Category
Browse igneous and mineral specimens identified by the Rock Identifier community.
Basalt
Mafic Igneous Rock (primarily Plagioclase Feldspar and Pyroxene)
Astrophyllite
Potassium Sodium Iron Manganese Titanium Silicate Hydroxide (K3NaFe7Ti2Si8O24(OH)7)
Amazonite
Potassium Feldspar (Microcline), K(AlSi3O8)
Smoky Quartz
Silicon Dioxide (SiO2)
Granite (specifically Rapakivi Granite)
Phaneritic Felsic Igneous Rock (Granite)
Granodiorite
Granodiorite (intermediate plutonic rock)
Blue Topaz
Al2SiO4(F,OH)2 (Fluorine-bearing aluminum silicate)
Amethyst (Geode)
Silicon Dioxide (SiO2) with iron impurities
Milky Quartz
Silicon dioxide (SiO2)
Yellow Quartz (Citrinated Quartz)
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Lapis Lazuli
Lapis Lazuli (Complex silicate mineral mix including Lazurite, Pyrite, and Calcite)
Moss Agate
Chalcedony (Silicon Dioxide, SiO2) with inclusions
Basalt
Basalt (Mafic volcanic rock)
Red Scoria (Lava Rock)
Vesicular Basalt / Scoria
Granite
Granite (Phaneritic igneous rock)
Basalt with Quartz Veining
Amygdaloidal Basalt (predominately SiO2 and (Na,Ca)(Si,Al)4O8)
Gold Ore in Quartz
Auriferous Quartz (Au + SiO2)
Sodalite in Matrix (often called Blue Marble or Sodalite-Syenite)
Sodalite-bearing Syenite / Na8Al6Si6O24Cl2 (Sodalite component)
Granodiorite
Granodiorite (Intermediate intrusive igneous rock)
Granite (White Granite variant)
Phaneritic Plutonic Rock (High-silica Felsic)
Granite
Granite (Alkali feldspar, Plagioclase feldspar, and Quartz)
Granite
Phaneritic Igneous Rock (composed primarily of Quartz SiO2, Alkali Feldspar (K,Na)AlSi3O8, and Plagioclase Feldspar)
Granite
Granitoid
Graphite
Graphite (Native Carbon), Formula: C
Quartz Pebble
Silicon Dioxide (SiO2)
Corundum
Corundum (Al2O3)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Greenschist
Greenschist (chlorite-epidote schist)
Sapphire (Corundum)
Corundum (Al2O3)
Granite Cobble
Granite (Phaneritic Igneous Rock)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Pyrite (Iron Pyrite)
Iron Sulfide (FeS2)
Pebble
Clast (specifically a granule or small pebble)
Metagabbro / Epidote Gneiss
Epidote bearing Hornblende Gneiss
Obsidian
Volcanic glass (mainly SiO2 with inclusions)
Green Aventurine
Silicon Dioxide (Quartz with Fuchsite inclusions), SiO2
Gneiss (specifically a granitic gneiss cobble)
Gneiss (high-grade regional metamorphic rock)
Obsidian
Obsidian (Volcanic Glass)
Obsidian (Black Obsidian)
Obsidian (Volcanic Glass)
Graphic Granite (Zebra Rock)
Pegmatitic Granite (composed of Quartz and K-Feldspar)
Sunstone
Plagioclase Feldspar (Na,Ca)(Al,Si)4O8