Sandstone (likely Siltstone or Mudstone variety)
Clastic Sedimentary Rock (primarily SiO2 with iron oxides)
Category
Browse organic (non rock) specimens identified by the Rock Identifier community.
Sandstone (likely Siltstone or Mudstone variety)
Clastic Sedimentary Rock (primarily SiO2 with iron oxides)
Limestone (Fossiliferous)
Calcium Carbonate (CaCO3)
River Rock
Silica-rich water-worn rock
Fossiliferous Limestone
Biogenic Sedimentary Rock (Calcium Carbonate, CaCO3)
Fossiliferous Limestone
Carbonate sedimentary rock with trace fossils (CaCO3)
Chert (Jasper/Mudstone)
Silicon Dioxide (SiO2)
Chert Nodule
Microcrystalline Quartz (SiO2)
Chert (Gray Chalcedony)
Microcrystalline Quartz (SiO2)
Chert (or Fossiliferous Limestone)
Microcrystalline Quartz (SiO2) / Calcium Carbonate (CaCO3)
Green Chert (Jasper)
Silicon Dioxide (SiO2)
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Tree Agate
Dendritic Agate (Silicon Dioxide, SiO2)
Weathered iron-rich sandstone or ironstone cobble
Ferruginous sandstone/ironstone, chiefly quartz (SiO₂) cemented or stained by iron oxides and hydroxides
Fossiliferous Chert
Silicon Dioxide (SiO2) with fossil inclusions
Sandstone Concretion
Clastic sedimentary rock (primarily Quartz SiO2)
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Asphalt
Asphalt concrete
Chert (Brecciated River Cobble)
Silicon Dioxide (SiO2)
Obsidian
Volcanic Glass (Amorphous Silica)
Chert (Flint)
Silicon dioxide (SiO2)
Chert (specifically Flint or Jasper variant)
Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (Iron-Stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert Pebble
Microcrystalline Quartz (SiO2)
Coral Rock (Coquina)
Biogenic Limestone (Calcium Carbonate - CaCO3)
Chert (Iron-stained)
Chert (SiO2)
Fossiliferous Limestone (Coquina / Shell Limestone)
Biogenic Limestone (CaCO3)
Tufa (Limestone)
Calcareous Tufa (CaCO3)
Chert (Chert Pebble)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Pink Anthracite Coal (dyed)
Anthracite Coal (Artificially Colored)
Chert (Iron-stained)
Chert (SiO2)
Chert (Yellow Jasper/Flint)
Microcrystalline Quartz (SiO2)
Chert (Tan/Yellow variety)
Microcrystalline quartz (SiO2)
Chert (or Flint)
Chert (Sedimentary Cryptocrystalline Sio2)
Chert (Flint)
Chert (Microcrystalline or cryptocrystalline Quartz, SiO2)
Fossil Coral (Honeycomb Coral)
Favosites (extinct genus of Tabulate coral)
Chert (Arrowhead variety)
Chert (SiO2)
Ironstone Concretion
Siderite / Hematite-bearing Sedimentary Rock
Chert (River Pebble)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Banded Chert (Ironstone type)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Chert Nodule in Limestone (Flint in Chalk)
SiO2 (Microcrystalline Quartz) in CaCO3 (Calcite)