Red Sandstone or Brick Fragment
Arenite (if sandstone)
Category
Browse anthropogenic (human made) sedimentary like material specimens identified by the Rock Identifier community.
Red Sandstone or Brick Fragment
Arenite (if sandstone)
Banded agate pendant (likely carnelian or brown-and-white chalcedony agate)
Agate, a banded variety of chalcedony; microcrystalline quartz, SiO₂, with iron-oxide coloration
Flint (or Chert with cortex)
Silicon dioxide (SiO2)
Chert (and Flint)
Silicon Dioxide (SiO2)
Chert (varieties include Flint and Jasper)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
Slag
Ferrous Slag (Amorphous calcium-magnesium-aluminum silicates)
Engineered Quartz Stone
Agglomerated Quartz (SiO2 + Polymer Resin)
Chert (varietal: Flint/Jasper)
Silicon Dioxide (SiO2)
Quartzite / Chert Nodular Rock
Silicon Dioxide (SiO2) / Microcrystalline Quartz
Sandstone
Arenite (composed primarily of SiO2)
Chalcedony (Chert/Flint variety)
Silicon Dioxide (SiO2)
Chert (variations include Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Lapis lazuli and green-blue chalcedony jewelry
Lapis lazuli: lazurite-bearing metamorphic rock, chiefly lazurite (Na₃Ca(Al₃Si₃O₁₂)S) with calcite and pyrite; second stone: likely chrysoprase or green-blue chalcedony (microcrystalline quartz, SiO₂)
Sandstone
Arenite (SiO2 composition dominant)
Chert (Jasper/Flint)
Silicon Dioxide (SiO2)
Chert (Honey Chert / Flint)
Silicon Dioxide (SiO2)
Asphalt Concrete
Bituminous conglomerate
Chert / Flint
Silicon Dioxide (SiO2)
Sandstone
Arenite (SiO2, often with CaCO3 or Fe2O3 cement)
Coquina
Bioclastic Limestone
Chert (Jasper/Flint)
Microcrystalline Quartz (SiO2)
Chert / Flint
Silicon Dioxide (SiO2)
Engineered Quartz (Quartzite look-alike)
Silicon Dioxide (SiO2) composite
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (Common Variety, Jasper)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Sea Glass
Amorphous Silicon Dioxide (Man-made glass weathered by nature)
Tumbled milky quartz
Quartz (silicon dioxide, SiO₂)
Slag (Industrial Glassy Byproduct)
Anthropogenic silicate byproduct (Slag)
Chert (often called Flint in various colors)
Silicon Dioxide (SiO2)
Chert / Flint
Silicon Dioxide (SiO2)
Chert (Chert Nodule)
Silicon Dioxide (SiO2)
Coquina
Biogenic Limestone (mostly Calcium Carbonate, CaCO3)
Chert / Flint
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert
Silicon dioxide (SiO2)
Chert (specifically Yellow/Honey Jasper variety)
Cryptocrystalline Quartz (SiO2)
Chert / Flint
Silicon dioxide (Microcrystalline Quartz, $SiO_2$)
Chert
Chert (SiO2)