Obsidian
Volcanic Glass (SiO2)
Category
Browse not a rock or mineral (anthropogenic material) specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass (SiO2)
Vesicular Basalt (or Porphyritic Scoria)
Vesicular Basalt
Granite
Granite (Felsic Plutonic Rock)
Druzy Quartz (on Chalcedony/Agate base)
Silicon Dioxide (SiO2)
White Quartz
Silicon Dioxide (SiO2)
Porous Quartzite
Metamorphosed Quartz-rich Sandstone (SiO2)
Granite
Granite (Felsic Plutonic Rock)
Gold-Bearing Quartz
Silicon Dioxide with Native Gold (SiO2 + Au)
Rose Quartz
SiO2 (Silicon Dioxide with trace amounts of titanium, iron, or manganese)
Rose Quartz
Quartz (Silicon Dioxide with trace inclusions of dumortierite, Al7(BO3)(SiO4)3O3)
Gneiss (High-Grade Metamorphic Rock)
Gneiss (primarily composed of Quartz, Feldspar, and Mica/Amphiboles)
Sandstone (Quartzite-rich)
Clastic Sedimentary Rock (primarily SiO2)
Sandstone
Arenite (SiO2 primarily)
Weathered Sandstone with Algae Growth
Arenite
Sandstone
Arenite (SiO2 based)
Sandstone (likely Calcareous or Micaceous)
Clastic sedimentary rock (primarily Quartz with Cementing Agents)
Quartz Geode (partially opened)
Silicon Dioxide (SiO2) with iron staining
Gold Nugget
Native Gold (Au)
Sandstone (likely Graywacke or Arkosic varieties)
Arenite (composed primarily of SiO2)
Red Jasper
Red Jasper (variety of Chalcedony, SiO₂)
Pyrite
Iron Sulfide (FeS2)
Bronzite
MgSiO3 (Enstatite with 10-30% FeSiO3 in solid solution)
Red Jasper
Jasper (Silicate mineral - SiO2)
Chert (Iron-stained)
Chert (Microcrystalline Quartz, SiO2)
Quartz (Raw Chunk)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Digital Multimeter (Synthetic Object)
Digital Multimeter (DMM)
Chalcedony (Botryoidal Agate vein)
Chalcedony (Microcrystalline Quartz) - SiO2
Opal
Hydrated Silica (SiO2·nH2O)
Amethyst (Chevron Amethyst)
Amethystine Quartz (SiO2)
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Bauxite
Hydrated Aluminum Oxides (primarily Gibbsite Al(OH)3, Boehmite γ-AlO(OH), and Diaspore α-AlO(OH))
Chert (often called Flint in this context)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Granodiorite
Granodiorite (Intermediate intrusive igneous rock)
Mica Schist
Mica Schist (predominantly Muscovite or Biotite sheet silicates)
Garnet Schist
Garnet-bearing Mica Schist (variety of compositions, often Al2SiO5 with X3Y2(SiO4)3)
Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')
Calcite (CaCO3)
Herkimer Diamond in Matrix
Quartz (SiO2) in Dolostone (CaMg(CO3)2)
Olivine (Peridotite)
(Mg,Fe)2SiO4 (Magnesium Iron Silicate)
Quartz (River Pebble)
Quartz (SiO₂ - Silicon Dioxide)