Sandstone (with manganese staining)
Clastic sedimentary rock (primarily SiO2)
Category
Browse rock (likely sedimentary) specimens identified by the Rock Identifier community.
Sandstone (with manganese staining)
Clastic sedimentary rock (primarily SiO2)
Sandstone (with banding/weathering)
Clastic Sedimentary Rock (primarily SiO2)
Sandstone
Arenite (SiO2-rich)
Sandstone (Greywacke/Lithic Sandstone)
Arenite (composed primarily of SiO2)
Tumbled quartz-rich pebble
Microcrystalline quartz (SiO₂), possibly weathered chert or chalcedony
Sandstone
Arenite (primarily SiO2)
Smoky Quartz and Biotite Schist
Quartz-Biotite Schist (SiO2 + K(Mg,Fe)3AlSi3O10(F,OH)2)
Banded Gneiss
Gneiss (complex metamorphic silicate rock)
Sandstone
Clastic Sedimentary Rock (composed mostly of quartz, SiO2)
Basalt or Siltstone Pebbles
Mafic volcanic rock (Basalt) or Indurated Siltstone
Metallic sulfide ore, likely pyrite-bearing rock
Pyrite (FeS₂), possibly with chalcopyrite and quartz/host rock
Black Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Sandstone (clastic)
Clastic Sedimentary Rock (primarily composed of SiO2)
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Jasper
Chalcedony (Microcrystalline Quartz) - SiO2
Granitic Gneiss
Gneiss (containing Potassium Feldspar and Quartz)
River Stones (Quartzite and Sandstone)
Quartzite / Sedimentary Rock (SiO2 dominant)
Chalcedony (Agate)
Silicon Dioxide (SiO2)
Breccia Pebble
Sedimentary Breccia
Sandstone (Green/Yellow Siltstone variant)
Arenite or Siltstone (primarily SiO2 with mineral staining)
Chert (Common Opal/Jasper variety)
Microcrystalline Quartz (SiO2) with hydration
Jasper
Silicon dioxide (SiO2) with impurities
Chert Pebble
Microcrystalline quartz (SiO2)
Sandstone (likely Arkosic or Lithic Sandstone)
Arenite (composed primarily of SiO2 with various lithic fragments)
Chert (Jasper/Agate variety)
Microcrystalline Quartz (SiO2)
Amethyst Geode Fragment
Amethyst (Silicon Dioxide, SiO2) with Quartz matrix
Chert (Gray Chalcedony)
Microcrystalline Quartz (SiO2)
Sandstone (with potentially metamorphic or basaltic bands)
Arenite / Lithic Wacke
Likely weathered sandstone or iron-stained sedimentary fragment
Quartz-rich sandstone; exact identification requires testing
Red Sandstone
Arenite (SiO2 with Fe2O3)
Sandstone Concretion
Arenaceous concretion (primarily SiO2 with Fe2O3 staining)
Dyed Agate Slice
Silicon Dioxide (SiO2)
Sandstone (likely Ferruginous)
Sandstone (SiO2 with iron oxides)
Chert (Quartz Variety)
Microcrystalline / Cryptocrystalline Quartz (SiO2)
Sandstone
Arenite (SiO2 dominant)
Rounded white pebble, likely quartz-rich rock
Most consistent with quartzite or milky-quartz pebble; exact identification requires testing
Sandstone (Quartzose Sandstone)
Arenite (primarily SiO2)
Fossiliferous Siltstone
Clastic Sedimentary Rock with Fossil Inclusions
Chert (River Pebble with Liesegang Rings)
Microcrystalline Silicon Dioxide (SiO2)
Concretion
Septarian concretion (likely containing Calcite or Siderite)
Bivalve Fossil (Clam)
Class Bivalvia, likely Mercenaria or similar genus
Quartz Geode
Quartz (Silicon Dioxide - SiO2) within a Chalcedony and Limonite shell