Black Onyx
Chalcedony (SiO2) with parallel banding
Category
Browse mineral (silicate variety) specimens identified by the Rock Identifier community.
Black Onyx
Chalcedony (SiO2) with parallel banding
Quartz (Clear / Rock Crystal)
Silicon Dioxide (SiO2)
Jasper (Iron-stained Chert)
Silicon Dioxide (SiO2) with impurities of Iron Oxide
Libyan Desert Glass
Tektite (high-silica impact glass), SiO2 + tracing minerals
Chert (Quartz)
Microcrystalline Silica (SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Greenstone / Glauconitic Siltstone
Metabasalt or Glauconite-rich Sedimentary Rock
Yellow Chalcedony (Agate/Chert)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Banded Calcite (often sold as Onyx or Mexican Onyx)
Calcite (Calcium Carbonate, CaCO3)
Quartzite
Quartzite (SiO2)
Yellow Jasper
Silicon Dioxide (SiO2) with hydrated iron oxide impurities (Goethite)
Chert (Red Jasper)
Silicon Dioxide (SiO2)
Dyed Agate
Silicon Dioxide with artificial pigment (SiO2)
Chert (Polished Gemstone / River Stone)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Quartzite
Quartzite (SiO2)
Quartzite
Quartzite (primarily SiO2)
Quartzite
Quartzite (primarily SiO2)
Banded Calcite (often sold as 'Mexican Onyx')
Calcite (Calcium Carbonate, CaCO3)
Chalcedony (Agate/Chert)
Microcrystalline Quartz (SiO2)
Cullet (Slag Glass)
Amorphous Silica (Industrial byproduct)
Chert (specifically Yellow or River Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Fossilized Brachiopod
Phylum Brachiopoda (General mineral composition: Calcite/CaCO₃ or Silica/SiO₂)
Ocean Jasper (Orbicular Jasper)
Spherulitic Chalcedony (SiO2)
Chert (Jasper variation)
Microcrystalline Quartz (SiO2)
Red Jasper
Jasper (Silicon Dioxide, SiO2)
Iron-stained Quartz (with Limonite/Hematite)
Silicon Dioxide (SiO2) with Iron Oxide inclusions (FeO(OH) or Fe2O3)
Banded Iron Formation (BIF) with Quartz
Banded Iron Formation, often composed of alternating layers of hematite (Fe2O3) or magnetite (Fe3O4) and chert (microcrystalline quartz, SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Rhyolite (Porphyritic)
Rhyolite (Felsic Extrusive Igneous Rock)
Ocean Jasper
Orbicular Jasper (SiO2)
Red Jasper (Banded Jasper)
Silicon Dioxide (SiO2) with Hematite impurities
Banded Calcite (often marketed as Mexican Onyx or Onyx Marble)
Calcite (Calcium Carbonate, CaCO3)
Slag (Industrial Glass)
Anthropogenic Amorphous Vitreous Silicate
Opal
Hydrated Silica (SiO2·nH2O)
Quartz (Milky or Smoky Quartz)
Quartz (Silicon Dioxide, SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Chert (Common Opal/Jasper variety)
Microcrystalline Quartz (SiO2) with hydration
Jasper
Silicon Dioxide (SiO2)
Cobalt Glass Slug (Cullet)
Man-made Silicate Glass with Cobalt Oxide (CoO)
Chalcedony or Chert/Jasper with secondary mineral staining
SiO2 (for chalcedony/quartz) with possible secondary copper minerals (e.g., CuSiO3·nH2O for chrysocolla, Cu2(CO3)(OH)2 for malachite) or iron oxides/hydroxides.
Ocean Jasper (Orbicular Jasper)
Spherulitic Chalcedony (SiO2)