Blue Sapphire (likely costume glass imitation)
Corundum (Al2O3) with iron/titanium impurities
Category
Browse industrial byproduct (anthropogenic material) specimens identified by the Rock Identifier community.
Blue Sapphire (likely costume glass imitation)
Corundum (Al2O3) with iron/titanium impurities
Quartz Pebble (Chalcedony/Agate variety)
Silicon Dioxide (SiO2)
Sandstone with Concretions / Liesegang Rings
Arenite with iron oxide banding
Quartz Geode (Water-worn)
Silicon Dioxide (SiO2)
Marble
Recrystallized Calcite (CaCO3)
Gold in Quartz
Hydrothermal Quartz with Native Gold (SiO2 with Au)
Vesicular Basalt
Extrusive Mafic Igneous Rock (Vesicular Basalt)
Diamond in Kimberlite
Kimberlite Matrix with Carbon (Diamond)
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
Jasper
Silicon dioxide (SiO2)
Chert (Jasper variation)
Microcrystalline Quartz (SiO2)
Chert (or Chalcedony)
Microcrystalline Quartz (SiO2)
Limonite (Ironstone)
Limonite (mixture of hydrated iron oxides, primarily Goethite α-FeO(OH))
Jasper Agate
Silicon dioxide (SiO2)
Limonite (Iron Ore)
Limonite (Hydrous iron(III) oxide-hydroxide mixture, primarily FeO(OH)·nH2O)
Pyrite (Fool's Gold) Cube
Iron Sulfide (FeS2)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Bituminous Coal
Bituminous coal (Carbonaceous sedimentary rock)
Pumice
Pumiceous rhyolite
Pumice
Pumice (Vesicular Felsic Glass)
Bituminous Coal
Organic Sedimentary Rock (Carbon-based)
Quartzite River Stone
Quartzite (SiO2)
Quartzite (Milky)
Quartzite (SiO2)
Carborundum (Silicon Carbide)
Silicon Carbide (SiC) / Moissanite (natural form)
Quartz Pebble
Silicon Dioxide (SiO2)
Fuchsite Quartzite
Fuchsite-bearing Quartzite
Quartz with Iron Stains
Quartz (SiO2) with iron oxide/hydroxide staining
Jasper
Jasper (Silica/Silicon Dioxide, SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Agate (Chert/Chalcedony)
Silicon Dioxide (SiO2)
Diamond (or Cubic Zirconia)
C (Carbon) or ZrO2 (Zirconium Dioxide)
Vesicular Rhyolite
Extrusive igneous rock (high-silica rhyolite)
Silver (Jewelry Specimen)
Native Silver (Chemical Formula: Ag)
Basalt Water-Worn Pebble
Aphanitic Mafic Igneous Rock
Man-made Blank Ammunition (Brass)
CuZn (Cartridge Brass - roughly 70% Copper, 30% Zinc)
Titanium-coated Metal Cube (Man-made Fidget Toy)
Titanium-anodized or electroplated alloy (e.g., Ti-coated Zinc or Aluminum)
United States Quarter Dollar
Cupronickel Clad Alloy (75% Copper, 25% Nickel over a 100% Copper core)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Chondrite Meteorite
Ordinary Chondrite (S-type Asteroid fragment)
Pyrite Geode
Iron Disulfide (FeS2)
Siltstone Pebble
Siltstone
Sandstone
Arenite (primarily SiO2)