Basalt River Pebble
Basalt
Category
Browse not a rock specimens identified by the Rock Identifier community.
Basalt River Pebble
Basalt
Basalt with Scoria and potential Olivine/Pyroxene inclusions
Vesicular Basalt
Lapis Lazuli
Lapis Lazuli (Rock containing Lazurite, Calcite, and Pyrite)
River Stone / Pebble
Clastic Sediment (composed largely of Quartz, Feldspar, and various rock fragments)
Sandstone (with potential fossil inclusions)
Clastic sedimentary rock (primarily SiO2)
Granite
Granite (Phaneritic Quartz-Feldspar rock)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Sandstone (Fossiliferous)
Clastic Sedimentary Rock (primarily SiO2)
Porphyry
Porphyritic Rhyolite or Andesite
Basalt (Polished pebble)
Basalt (Aphanitic mafic volcanic rock)
Basalt (Vesicular and Scoria)
Basalt (extrusive volcanic rock)
Unakite
Epidotized Granite
Sandstone
Sandstone (Clastic Sedimentary Rock)
Sandstone (likely a river or beach pebble)
Sandstone (a clastic sedimentary rock)
Gneiss
Gneiss (a type of metamorphic rock)
Asphalt (Bituminous Concrete)
Bituminous mix containing aggregates and petroleum-based binder (CnH2n+2)
Milky Quartz
Silicon Dioxide (SiO2)
Yellow Quartz (Citrine or Iron-Stained Quartz)
Silicon Dioxide (SiO2)
Chert (Jasper variation)
Silicon dioxide (SiO2)
Concrete Rubble with Aggregate
Hardened Portland Cement Paste with Coarse Aggregate
Jasper
Silicon dioxide (SiO2)
Quartz (Milky/Common)
Silicon Dioxide (SiO2)
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Magnetite
Magnetite (Fe3O4)
Quartz
Silicon Dioxide (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Fire Opal (Common/Precious in Matrix)
Hydrated Silica (SiO2·nH2O)
Sandstone Concretion
Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)
Ferruginous Quartz
Quartz with Iron Oxide inclusions (SiO2 + Fe2O3)
Glacial Erratic (Sandstone/Quartzite)
Glacial Erratic specimen (likely Orthoquartzite or Feldspathic Sandstone)
Grey Agate
Silicon Dioxide (SiO2) - Variety of Chalcedony
Conglomerate
Conglomeratic Sandstone
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Garnet-Bearing Schist
Almandine Garnet Micaceous Schist
Chert / Flint
Microcrystalline Quartz (SiO2)
Quartz (Milky/Common)
Quartz (Silicon Dioxide, SiO2)
Grey Agate (Tumbled)
Silicon Dioxide (SiO2)
Chert (often called Flint in dark varieties)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Quartz
Silicon Dioxide (SiO2)
Chert (Iron-stained)
Chert (Cryptocrystalline Silica, SiO2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)
Desert Rose (Baryte or Gypsum Rose)
Baryte (BaSO4) or Gypsum (CaSO4·2H2O)