Sandstone (Ferruginous)
Arenite (SiO2 with Fe2O3 inclusions)
Category
Browse industrial byproduct (often mistaken for obsidian or mineral) specimens identified by the Rock Identifier community.
Sandstone (Ferruginous)
Arenite (SiO2 with Fe2O3 inclusions)
Basalt
Extrusive Mafic Igneous Rock (composed primarily of plagioclase, pyroxene, and olivine)
Pumice
Pumice (a highly vesicular volcanic glass)
Peridot
Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)
Basalt
Basalt (Aphanitic extrusive igneous rock)
Quartzite
Quartzite (composed primarily of SiO2)
Ruby (Raw/Rough)
Corundum (Al2O3 with Chromium trace)
Pink Satin Spar (Satin Spar Selenite Dyed)
Gypsum (CaSO4·2H2O)
Chert (specifically Flint or Dark Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sodalite (blue beads) and Clear Quartz (clear beads)
Sodalite: Na4Al3Si3O12Cl; Quartz: SiO2
Agate
Agate (Silicon Dioxide, SiO2)
Red Swirl Beads (Likely Resin or Glass, simulating Red Jasper or Agate)
N/A (for the beads as pictured); Red Jasper: SiO2 (Chert variety); Red Agate: SiO2 (Chalcedony variety)
Quartzite Pebble
Quartzite (primarily Silicon Dioxide, SiO2)
Quartzite
Quartzite (primarily SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Agate (specifically a Blue Agate Geode Slice)
Chalcedony (cryptocrystalline variety of Quartz); SiO2
Peridot (Olivine)
Magnesium Iron Silicate (Mg, Fe)2SiO4
Granodiorite
Granodiorite (Intermediate intrusive igneous rock)
Tumbled Stone Collection (featuring Tiger's Eye, Rose Quartz, and Moss Agate)
Mixed Silicates and Oxides (predominantly SiO2 group minerals)
Agate Geode
Chalcedony (SiO2 - Silicon Dioxide)
Quartzite
Quartzite (primarily SiO2)
Anthracite Coal
Anthracite (Carbon-rich Sedimentary-to-Metamorphic Rock)
Red Sandstone
Arenite (with Iron Oxide pigmentation)
Red Sandstone
Arenite (primarily Quartz with Iron Oxide coating)
Quartzite Pebble
Quartzite (primarily SiO2)
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.
Quartzite
Quartzite (SiO2)
Rutilated Quartz
Quartz (SiO2) with Rutile inclusions (TiO2)
Agate
Agatized Chalcedony (SiO2)
Diamond
Diamond (C)
Quartz (Small Fragment)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Milky Quartz with Iron Inclusions
Quartz (Silicon Dioxide, SiO2)
Quartz Druzy (Geode Fragment)
Silicon Dioxide (SiO2)
Amethyst (Raw Quartz)
Amethyst (Silicon Dioxide with Iron impurities, SiO2)
Diamond
Diamond (pure Carbon, C)
Ruby
Corundum (Al2O3 with chromium impurities)
Quartz Pebble
Silicon Dioxide (SiO2)
Chalcedony (Common Opal variant)
Silicon dioxide (SiO2) with varying levels of hydration
Red Garnet (Pyrope or Almandine)
Garnet Group (A3B2(SiO4)3)
Diamond (in jewelry setting)
Carbon (C)
Iolite (Cordierite)
Cordierite (Magnesium Aluminum Silicate), Mg2Al4Si5O18