Sandstone (likely Graywacke or Arkose variant)
Clastic Sedimentary Rock (SiO2 with assorted lithic fragments)
Category
Browse sedimentary (with some aspects of mineral replacement) specimens identified by the Rock Identifier community.
Sandstone (likely Graywacke or Arkose variant)
Clastic Sedimentary Rock (SiO2 with assorted lithic fragments)
Vuggy Chert / Silicified Limestone
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Weathered chert or siliceous limestone
Microcrystalline quartz (SiO₂), possibly with carbonate minerals
Chert (specifically Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Favosites Fossil (Honeycomb Coral)
Favosites (Extinct genus of Tabulate Coral)
Gneiss
Gneiss
Sandstone (likely Graywacke or Siltstone variety)
Clastic Sedimentary Rock (SiO2 with assorted mineral fragments)
Red Jasper (Chalcedony)
Silicon Dioxide (SiO2) with iron oxide inclusions
Pyrite
Iron Sulfide (FeS2)
Chert (Jasper)
Microcrystalline Quartz (SiO2) with iron oxide inclusions
Petrified Wood
Silicified Wood / Fossilized Wood (SiO2)
Flint
Microcrystalline Quartz (SiO2)
Flint
Silicon dioxide (SiO2) - cryptocrystalline quartz
Flint Pebble
Silicon Dioxide (Microcrystalline Quartz, SiO2)
Chert / Flint Arrowheads and Artifacts
Cryptocrystalline quartz (SiO2)
Flint
Microcrystalline quartz (SiO2)
Flint
Silicon Dioxide (SiO2)
Chert (Pebble)
Silicon Dioxide (SiO2)
Chert (Flint/Nodule)
Silicon Dioxide (SiO2)
Chert (Flint) Nodule
Microcrystalline Quartz (SiO2)
Flint (Chert Nodule)
Microcrystalline Quartz (SiO2)
Chert (Flint) with Limestone Coating
Silicon Dioxide (SiO2) with Calcium Carbonate (CaCO3) cortex
Flint
Silicon Dioxide (SiO2) - Chert variety
Amber Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (specifically Flint or Common Opal/Chalcedony mix)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Chert (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Flint
Chert (Silicon dioxide, SiO2)
Brachiopod Fossil
Phylum Brachiopoda (replaced by Calcite or Silica)
Chert (Arrowhead variety)
Chert (SiO2)
Chert (with Quartz)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Chert (SiO2)
Flint or Chert
Microcrystalline Quartz (SiO2)
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Gneiss with Quartz Veining
Gneiss (High-grade Metamorphic Rock)
Sandstone Concretion
Clastic sedimentary rock (primarily Silica, SiO2, or Calcium Carbonate, CaCO3)
Geode (Quartz chalcedony variety)
SiO2 (Silicon Dioxide)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert Nodule
Microcrystalline Quartz (SiO2)
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Fossilized Coral
Cnidaria fossil / Calcite-replaced coral