Chert (and/or Flint)
Microcrystalline Quartz (SiO2)
Category
Browse synthetic polymer (polylactic acid) specimens identified by the Rock Identifier community.
Chert (and/or Flint)
Microcrystalline Quartz (SiO2)
Quartzite
Quartzite (primarily SiO2)
Jasper with Quartz Vein
Silicon Dioxide (SiO2) with impurities
Blue Quartzite
Blue Quartzite (Primary mineral: Quartz, SiO2 with magnesio-riebeckite or crocidolite inclusions)
Quartz (Milky/Common variety)
Silicon Dioxide (SiO2)
Chalk (Limestone variant)
Calcium Carbonate (CaCO3)
Quartzite
Quartzite (primarily SiO2)
Fossiliferous Limestone with Rugose Coral
Calcite (CaCO3) containing a Rugosa (Horn Coral) fossil
Azurite
Azurite (Cu3(CO3)2(OH)2)
White Marble
Recrystallized Calcite (CaCO3)
Quartzite
Quartzite (primarily SiO2)
Yellow Quartzite (River Cobble)
Quartzite (mainly SiO2)
Quartz Pebble (River Rock)
Silicon Dioxide (SiO₂)
Sandstone (Quartzose)
Arenite (composed mainly of SiO2)
Marble (Carrara style)
Recrystallized Calcite-rich Metamorphic Rock (CaCO3)
Orange Quartzite (Tumble-polished)
Quartzite (primarily SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Azurite
Azurite (Cu3(CO3)2(OH)2)
Limestone
CaCO3 (Mainly Calcite or Aragonite)
Malachite
Copper carbonate hydroxide, Cu2CO3(OH)2
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) in Rhyolitic Matrix
Quartzite (River Pebble)
Quartzite (SiO2)
Quartzite
Metamorphosed Quartz Sandstone (primarily SiO2)
Coquina
Coquina (Bioclastic Limestone)
Coquina
Biogenic Limestone
Travertine
Travertine (CaCO3 - Calcium Carbonate)
Limestone
Calcite (CaCO3)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
Orange Calcite (Cleavage Rhomb)
Calcite (Calcium Carbonate, CaCO3)
Yellow Calcite
Calcium Carbonate (CaCO3)
Calcite
Calcium Carbonate (CaCO3)
Banded Calcite (often marketed as Caribbean Calcite)
Calcium Carbonate (CaCO3) + Aragonite
Sandstone
Arenite (primarily SiO2)
Banded Calcite (often sold as 'Ocean Jasper' or 'Caribbean Calcite' variant)
Calcium Carbonate (CaCO3) with potential Aragonite inclusions
Blue Aragonite
Aragonite (Calcium Carbonate, CaCO3)
Quartzite
Quartzite (SiO2)
Optical Calcite (Iceland Spar)
Calcium Carbonate (CaCO3)
Quartzite with Iron Inclusions
Metamorphosed Sandstone (SiO2 dominated)
Yellow Calcite
Calcite (Calcium Carbonate, CaCO3)
Fossiliferous Limestone (containing Brachiopods)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Quartzite
Quartzite (SiO2)