Agate (Carnelian / Chalcedony)
Silicon Dioxide (SiO2)
Category
Browse industrial byproduct (often mistaken for obsidian or mineral) specimens identified by the Rock Identifier community.
Agate (Carnelian / Chalcedony)
Silicon Dioxide (SiO2)
Garnet Schist
Almandine-Garnet Mica Schist
Diamond
Diamond (pure Carbon, C)
Rough Diamond
Diamond (pure Carbon, C)
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
Aquamarine
Beryl (Be3Al2Si6O18 with iron impurities)
Carborundum (Silicon Carbide)
Silicon Carbide (SiC) / Moissanite (natural form)
Almandine Garnet
Almandine (Fe3Al2Si3O12)
Red Jasper
Jasper (Silicon Dioxide with Iron Oxide inclusions, SiO2)
Diamond (in jewelry setting)
Cubic Carbon (C)
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
Granitic Pegmatite
Coarse-grained Igneous Rock (Granitic composition: KAlSi3O8, SiO2)
Basalt
Extrusive Mafic Igneous Rock (composed primarily of plagioclase, pyroxene, and olivine)
Quartzite Pebble
Metamorphosed Quartz Sandstone (SiO2)
Granite Glacial Erratic
Granite (Phaneritic Quartz-Feldspar Plutonic Rock)
Marble
Crystalline Limestone (mostly CaCO3 / Calcium Carbonate)
Quartzite (River Cobble)
Quartzite (SiO2)
Basalt
Basalt (Aphanitic extrusive igneous rock)
Chert (or possibly Flint)
SiO2 (Silicon Dioxide)
Jasper
Silicon Dioxide (SiO2)
Marble
Recrystallized Calcite (CaCO3) Rock
Basalt
Basalt (Mafic volcanic rock)
Quartzite
Quartzite (composed primarily of SiO2)
Quartzite Pebble
Quartzite (primarily 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)
United States Quarter Dollar
Cupronickel Clad Alloy (75% Copper, 25% Nickel over a 100% Copper core)
Quartzite
Quartzite (primarily SiO2)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Sandstone (Ferruginous)
Arenite (SiO2 with Fe2O3 inclusions)
Peridot
Olivine (Magnesium Iron Silicate - (Mg, Fe)2SiO4)
Chert (specifically Flint or Dark Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Peridot (Olivine)
Magnesium Iron Silicate (Mg, Fe)2SiO4
Quartzite
Quartzite (primarily SiO2)
Anthracite Coal
Anthracite (Carbon-rich Sedimentary-to-Metamorphic Rock)
Sodalite (blue beads) and Clear Quartz (clear beads)
Sodalite: Na4Al3Si3O12Cl; Quartz: SiO2
Ruby (Raw/Rough)
Corundum (Al2O3 with Chromium trace)
Red Sandstone
Arenite (with Iron Oxide pigmentation)
Pink Satin Spar (Satin Spar Selenite Dyed)
Gypsum (CaSO4·2H2O)
Agate
Agate (Silicon Dioxide, SiO2)
Quartzite
Quartzite (primarily SiO2)
Tumbled Stone Collection (featuring Tiger's Eye, Rose Quartz, and Moss Agate)
Mixed Silicates and Oxides (predominantly SiO2 group minerals)
Smoky Quartz
Silicon Dioxide (SiO2)