Polished banded calcite (often sold as “onyx marble” or Mexican onyx)
Banded calcite, CaCO₃ (sometimes aragonite); decorative “onyx marble” is not true quartz onyx
sedimentary
Category
Igneous Or Metamorphic (Base Stone); Anthropogenic (Decoration)
Browse igneous or metamorphic (base stone); anthropogenic (decoration) specimens identified by the Rock Identifier community.
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Biotite Schist
Biotite Schist (predominantly K(Mg,Fe)3AlSi3O10(OH,F)2)
metamorphic
Milky Quartz Pebble
Crystalline Silicon Dioxide (SiO2)
mineral
Ferruginous Sandstone (Ironstone Nodules)
Ferruginous Sandstone with Limonite/Goethite coating (Fe2O3·H2O)
sedimentary
Gneiss
Gneiss (High-grade Metamorphic Rock)
metamorphic
Epidote
Epidote (Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH))
metamorphic
Granite Pebble
Granite (Phaneritic intrusive igneous rock comprising Quartz, Feldspar, and Mica)
igneous
Feldspathic Gneiss
High-grade Metamorphic Rock (Gneiss)
metamorphic
Slag
Ferrous Slag (Amorphous calcium-magnesium-aluminum silicates)
igneous (artificial/anthropogenic)
Ferro-silicate Slag
Industrial Vitrified Slag (High-silica amorphous glass)
Mineral byproduct (Anthropogenic)
Slag (Industrial Byproduct)
Artificial silicate/iron byproduct
Mineral description (Anthropogenic material)
Likely tumbled purple quartzite or jasper
Quartz-rich rock; exact identification is uncertain from the image
metamorphic
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
sedimentary
Sodalite
Sodalite - Na8(Al6Si6O24)Cl2
mineral
Mica
Mica group (often Muscovite or Biotite)
mineral
Amphibolite / Biotite Schist
Amphibolite (rich in Hornblende and Plagioclase feldspar)
metamorphic
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Greenstone (Epidisite / Chlorite Schist)
Metabasalt (often contains Epidote Ca2Al2(Fe3+,Al)(SiO4)(Si2O7)O(OH) and Chlorite)
metamorphic
Citrine
Silicon Dioxide (SiO2)
mineral
Road-surface aggregate (crushed stone)
Unidentifiable mixed lithic aggregate; likely basaltic/andesitic fragments with feldspar, quartz, and weathered rock
igneous
Quartz (Milky/Smoky variety on matrix)
Silicon Dioxide (SiO2)
mineral
River Pebble (Gneiss or Quartzite mixture)
Metamorphic rock (Commonly Gneissic)
metamorphic
Rounded quartzite pebble
Quartzite (predominantly recrystallized quartz, SiO₂)
metamorphic
Gold Ore in Quartz/Schist
Auriferous Quartz and Sulfide-bearing Schist
Metamorphic/Igneous (Hydrothermal)
Citrine Quartz
Silicon Dioxide (SiO2)
mineral
Citrine
Silicon Dioxide (SiO2) with iron impurities
mineral
Gneiss
Gneiss (Metamorphic Rock)
metamorphic
Labradorite
Labradorite (Plagioclase Feldspar Series - (Ca, Na)(Al, Si)4O8)
mineral
Aura Quartz Bead
Silicon dioxide (SiO2) with metal coating
mineral with artificial coating
White beach pebble, likely quartzite
Quartzite (predominantly quartz, SiO₂); identification is uncertain from the image alone
metamorphic
Amethyst
Amethyst (Silicon Dioxide, SiO2 with Iron impurities)
mineral
Blue Quartz with Dumortierite/Magnesio-riebeckite inclusions
Quartz (SiO2) containing Dumortierite (Al7(BO3)(SiO4)3O3)
igneous/metamorphic
Greenschist
Chlorite schist
metamorphic
Greenschist
Chlorite schist
metamorphic
Greenschist
Chlorite schist
metamorphic
Coquina / Fossiliferous Limestone
Calcareous bioclastic sedimentary rock (CaCO3)
sedimentary
Green Aventurine
Aventurine (Quartz variety), SiO2
metamorphic
Epidote
{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
mineral
Basalt River Stone
Extrusive mafic igneous rock (Basalt)
igneous
Green tumbled stone, possibly serpentine
Undetermined; appearance is consistent with serpentine-rich rock (serpentinite), but the image alone cannot confirm identification.
metamorphic
Iridescent schist or phyllite
Micaceous quartz-rich schist/phyllite, likely containing muscovite or chlorite
metamorphic
Citrine
Silicon Dioxide with iron impurities (SiO2)
mineral