Shale or Argillite
Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)
Category
Browse organic materia (not a rock or mineral) specimens identified by the Rock Identifier community.
Shale or Argillite
Shale (fine-grained clastic sedimentary rock) or Argillite (low-grade metamorphic rock derived from shale)
Chert (and Limestone) River Cobble
Microcrystalline Quartz (SiO2) within Calcium Carbonate (CaCO3)
Chert (Jasper/Flint variety)
Silicon Dioxide (SiO2)
Chert (often called Jasper or River Rock)
Chert (SiO2)
Chert / Jasper / Agate (Chalcedony Group)
Microcrystalline Quartz (SiO2)
Chert (Chert / Flint)
Silicon dioxide (SiO2) - Microcrystalline quartz
Chert (Nodule)
Silicon Dioxide (SiO2)
Black Pearl (Tahitian Pearl)
Aragonite / Calcite (CaCO3) with Conchiolin
Chert (variously identified as Flint)
Microcrystalline Quartz (SiO2)
Chert (Quartz Variety)
Chert (mostly SiO2 / Silicon Dioxide)
Pyrite in Shale
Iron Disulfide (FeS2) in Argillaceous Shale
Fossil Coral (Honeycomb Coral)
Favosites (extinct genus of Tabulate coral)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chert (Quartz Variety)
Chert (Silicon Dioxide, SiO2)
Chert (Yellow/Brown Jasper)
Silicon Dioxide (SiO2)
Chert (and/or River Pebble)
Microcrystalline silica (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Pearl
Calcium carbonate (CaCO3) as Aragonite or Calcite
Chert (Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (with Quartz veins)
Microcrystalline Quartz (SiO2)
Red Chert (Jasper)
Silicon Dioxide (SiO2)
Red Jasper
Jasper (Silicon Dioxide, SiO2)
Chert (Jasper/Ironstone variety)
Silicon Dioxide (SiO2) with iron oxide inclusions
Pink Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Chert (Nodular)
Microcrystalline Silica (SiO2)
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Coral Rock (Coquina)
Biogenic Limestone (Calcium Carbonate - CaCO3)
Chert (specifically Flint or Jasper variant)
Cryptocrystalline Quartz (SiO2)
Chert Nodule
Chert (Cryptocrystalline variety of Quartz, SiO2)
Chert (Nodular Chert)
Silicon Dioxide (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
Red Chert (Jasper)
Chert / Microcrystalline Quartz (SiO2)
Ferruginous Sandstone (Ironstone)
Sedimentary rock with Limonite/Goethite cement
Shungite
Non-crystalline carbon (high-carbon metamorphic rock)
Chert Pebble (Jasper variant)
Microcrystalline Quartz (SiO2)
Pearl
Calcium Carbonate (CaCO3) with Conchiolin
Amber
Succinite (Fossilized Tree Resin)
Shale or Argillite
Shale (sedimentary) / Argillite (metamorphic)
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Limestone (Weathered)
Calcium Carbonate (CaCO3)
Pyrite
Iron Sulfide (FeS2)
Chert (Jasper-bearing)
Chert (Silicon Dioxide, SiO2)