Amethyst
Quartz (Silicon Dioxide with Iron impurities), SiO2
Category
Browse industrial byproduct (often confused with igneous rocks or meteorites) specimens identified by the Rock Identifier community.
Amethyst
Quartz (Silicon Dioxide with Iron impurities), SiO2
Smoky Quartz
Silicon Dioxide (SiO2)
Magnetite with Pyrite or Chalcopyrite inclusions
Magnetite (Fe3O4) with Pyrite (FeS2)
Basalt
Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
Dyed Pumice
Vesicular Rhyolite (Artificial Coloration Addition)
Green Glass (often marketed as 'Obsidian' or 'Green Quartz')
Amorphous Silica (SiO2) with copper or chromium additives
Vesicular Basalt
Mafic Volcanic Rock (Basalt)
Malachite
Copper carbonate hydroxide Cu2CO3(OH)2
Pegmatite with Muscovite
Granitic Pegmatite (KAl2(AlSi3O10)(OH)2)
Apache Tear (Obsidian)
Obsidian / Amorphous Volcanic Glass (primarily SiO2)
Pink Feldspar (Orthoclase)
Orthoclase Feldspar (KAlSi3O8)
Pyrite
Iron Sulfide (FeS2)
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
Clear Quartz
Silicon Dioxide (SiO2)
Biotite Schist
Biotite Schist (predominantly K(Mg,Fe)3AlSi3O10(OH,F)2)
Chert (specifically Blue Chert/Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Pyrite
Iron Sulfide (FeS2)
Granite River Pebble
Phaneritic Felsic Igneous Rock (Granite)
Muscovite Mica
Muscovite (KAl2(AlSi3O10)(OH)2)
Orthoclase Feldspar
Orthoclase (KAlSi3O8)
Sodalite Syenite
Sodalite-bearing Syenite (Na8(Al6Si6O24)Cl2)
Smoky Quartz
Silicon Dioxide (SiO2)
Amethyst (Faceted Gemstone)
Silicon Dioxide (SiO2) with iron impurities
Vesicular Basalt
Basalt with vesicular texture
Labradorite
Labradorite ((Ca, Na)(Al, Si)4O8)
Amazonite
Potassium Feldspar (Microcline), K(AlSi3O8)
Granite
Phaneritic plutonic rock (Quartz, Alkali Feldspar, and Plagioclase)
Diorite
Intermediate plutonic igneous rock
Porphyry (likely Porphyritic Andesite or Basalt)
Porphyritic Igneous Rock
Ironstone Concretion (Nutstone)
Ironstone (with High Limonite/Hematite Content)
Agate (Fortification Agate)
Banded Chalcedony (SiO2)
Rhodonite
Manganese silicate (Mn,Fe,Mg,Ca)SiO3
Snowflake Obsidian
Volcanic Glass with Spherulite Inclusions (70-75% SiO2)
Granite (Alkali-feldspar Granite)
Granite (composed primarily of Quartz, K-Feldspar, and Plagioclase)
Giallo Ornamental Granite
Phaneritic Igneous Rock (composed of Quartz, Feldspar, and Mica)
Pink Quartzite
Quartzite (SiO2 with iron oxide inclusions)
Scoria (Lava Rock)
Scoria
Vesicular Basalt
Vesicular Basalt (Aphanitic Mafic Rock)
Fuchsite
Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)
Granite
Phaneritic plutonic rock (Quartz, Feldspar, Mica)
Diorite (Salt and Pepper Rock)
Diorite
Basalt River Cobble
Basalt (Composition primarily Plagioclase Feldspar and Pyroxene)