Moonstone
Adularia (orthoclase) or Albite (plagioclase), a potassium aluminum silicate of the feldspar group
Category
Browse igneous and mineral specimens identified by the Rock Identifier community.
Moonstone
Adularia (orthoclase) or Albite (plagioclase), a potassium aluminum silicate of the feldspar group
Indigo Gabbro
Gabbro (composed of plagioclase feldspar, pyroxene, and olivine)
Granite
Granite (a felsic intrusive igneous rock)
Citrine
Citrine (Silicon Dioxide, SiO2)
Sodalite
Na8(Al6Si6O24)Cl2 (Sodalite)
Basalt
Basalt (dominated by plagioclase feldspar and pyroxene)
Greenstone
Greenschist / Greenstone (Chlorite-Epidote facies)
Smoky Quartz
Quartz (SiO₂)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Epidote in Granite Gneiss
Epidote bearing Orthogneiss (Ca2(Al,Fe)3(SiO4)3(OH))
Diabase (Dolerite) Cobble
Diabase / Dolerite
Granite
Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)
Diorite
Diorite (Intermediate plutonic rock)
Arsenopyrite in Quartz Matrix
Arsenopyrite (FeAsS) with Quartz (SiO2)
Red Granite
Phaneritic Plutonic Rock (High Potassium Feldspar)
Amethyst (Tumbled/Polished)
Silicon Dioxide (SiO2) with iron impurities
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Folded Schist / Gneiss (Metamorphic Rock)
Regional Metaphoric Folded Outcrop (predominantly Schist/Gneiss)
Amazonite in Pegmatite Matrix with Smoky Quartz
K(AlSi3O8) - Microcline (var. Amazonite) with SiO2 (Quartz)
Citrine
Silicon Dioxide (SiO2) - Yellow Quartz variety
Rough Dark Green Sapphire
Corundum (Al2O3)
Gneiss (specifically a Banded Gneiss pebble)
Gneiss (High-grade Regional Metamorphic Rock)
Granodiorite
Phaneritic Granodiorite
Granite
Granite (composed primarily of Quartz SiO2, Feldspar (KAlSi3O8), and Mica)
Quartz
Quartz (SiO2 - Silicon Dioxide)
Sunstone
Oligoclase (a plagioclase feldspar variant), (Na,Ca)(Al,Si)4O8
Gneiss (Metamorphic Rock)
Gneiss (high-grade regional metamorphic rock)
Banded Agate (with small Geode cavity)
Silicon Dioxide (SiO2) - Chalcedony variety
Snowflake Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with Cristobalite inclusions)
Banded Gneiss
Gneiss (complex metamorphic silicate rock)
Obsidian
Obsidian (Amorphous volcanic glass, SiO2 rich)
Obsidian
Volcanic Glass (SiO2 rich)
Wonderstone (Banded Rhyolite)
Rhyolite (Silicon Dioxide with Iron Oxide impurities)
Vesicular Basalt (Iron-rich)
Scoriaceous Basalt / Oxidized Vesicular Basalt
Milky Quartz
Silicon Dioxide (SiO2)
Pegmatite with Smoky Quartz and Feldspar
Pegmatite (Quartz: SiO2, Feldspar: KAlSi3O8)
Amazonite (likely mixed with other feldspars/minerals)
Amazonite is a variety of Microcline, which is a tectosilicate mineral, formula KAISi3O8. The mixed beads could include other feldspars or quartz.
Obsidian (Black)
Obsidian (High-silica volcanic glass)
Mahogany Obsidian
Obsidian (SiO2 + Fe2O3)
Iron Meteorite Fragment
Siderite (Geological term for iron meteorite class - Fe/Ni alloy)
Schist
Schist
Quartz (likely Milky Quartz)
Quartz (SiO₂ - Silicon Dioxide)