Chert (often called Flint for darker varieties)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Category
Browse man made material specimens identified by the Rock Identifier community.
Chert (often called Flint for darker varieties)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Chert (and Jasper/Chalcedony mixture)
Microcrystalline Quartz (SiO2)
Coquina
Biogenic Limestone (Calcite, CaCO3)
Quartzite
Metamorphic Quartzite (SiO2)
Sandstone
Sandstone (composed predominantly of Quartz, SiO2, with Feldspar and Clay minerals)
Sandstone
Arenite (composed primarily of SiO2)
Coal (Anthracite / Bituminous)
Organic Sedimentary Rock (Carbon-based)
Tree Agate
Chalcedony (SiO2)
Chert (Nodule)
Chert (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Chert (and Flint)
Silicon Dioxide (SiO2)
Sandstone
Arenite
Sandstone
Clastic sedimentary rock (Quartz arenite/Arkose)
White Marble
Recrystallized Calcite (CaCO3)
Unakite
Altered Granite (Epidotized Granite)
Diamond (in jewelry setting)
Adamantine Carbon (C)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Polished blue-green glassy slag or coated mineral fragment
Most likely man-made colored glass/slag; exact composition cannot be determined visually
Goldstone
N/A (Synthetic Glass with Copper Inclusions)
Sandstone
Arenite
Chert (Flint)
Microcrystalline Quartz (SiO2)
Tektite
Impactite (Natural Silicate Glass)
Chert (Jasper/Flint variant)
Silicon Dioxide (SiO2)
Chert (Nodule/Pebble)
Chert (Silicon Dioxide, SiO2)
Coquina / Fossiliferous Limestone
Coquina (composed primarily of Calcium Carbonate / CaCO3)
Slate
Metamorphic pelitic rock
Sandstone (with iron staining)
Quartz Arenite / Ferruginous Sandstone
Sandstone (likely Fossiliferous)
Arenite / Fossiliferous Sandstone (SiO2 composition)
Yellow Chert (Chalcedony)
Microcrystalline Quartz (SiO2)
White Marble
Recrystallized Calcite Rock (CaCO3)
River Pebbles (Chert and Quartzite)
Sedimentary Clastic Rock (Silica-rich)
Diamond (as set in a metal alloy ring)
Diamond (Pure Carbon, C)
Sandstone
Arenite
Blue opalite (often sold as synthetic opal)
Opalite glass; amorphous hydrated silica if natural opal (SiO₂·nH₂O)
Iron Slag
Ferrous slag (primarily silicates and oxides of calcium, iron, and magnesium)
Sandstone
Sedimentary Rock (Quartz Sandstone)
Green Aventurine
Quartz (SiO2) with Fuchsite inclusions
Blue-beaded gemstone jewelry, likely lapis lazuli or dyed blue agate
Uncertain from the image; possible lazurite-bearing lapis lazuli (Na₃Ca(Si₃Al₃)O₁₂S) or blue chalcedony (SiO₂)
Artificial Rock Face (Faux Rock)
Glass Fiber Reinforced Concrete (GFRC)
Ferruginous Sandstone (Ironstone)
Clastic Sedimentary Rock (composed of SiO2 with Fe2O3/FeO(OH) cement)
Graphite
Graphite (Carbon, C)
Natural or Cultured Pearl
Calcium Carbonate (Aragonite and Conchiolin), CaCO3