Sandstone
Arenite (composed primarily of SiO2)
Category
Browse rock (likely sedimentary) specimens identified by the Rock Identifier community.
Sandstone
Arenite (composed primarily of SiO2)
Sandstone
Arenite (Quartz Sandstone)
Unidentified gray stone
Likely quartz-rich stone; exact identification is not possible from the image
Agate
Agate (a cryptocrystalline variety of Quartz, SiO₂)
Amygdaloidal Basalt with Secondary Minerals
Basalt containing secondary mineralization (likely Chlorite, Celadonite, or Zeolites)
Limonite/Goethite Iron Concretion
Hydrated iron oxide-hydroxide mixture (FeO(OH)·nH2O)
Druzy Quartz Geode
Silicon Dioxide (SiO2)
Quartz geode
Microcrystalline and crystalline quartz (SiO₂), likely chalcedony-lined geode
Sandstone
Sedimentary Rock (Quartz arenite)
Sandstone
Sedimentary Rock (Quartz Sandstone)
Waterworn Pebble / Quartzite
Metamorphic/Sedimentary rock fragment
Possible tektite or dark volcanic rock fragment
Uncertain; likely natural silicate glass (tektite) or basalt
Tumbled green jasper (probable serpentine-rich stone)
Jasper, microcrystalline quartz (SiO₂), possibly mixed with serpentine or chlorite
Limestone (River Pebble)
Calcite (Calcium Carbonate) - CaCO3
Sandstone
Arenite (primarily SiO2)
Sandstone
Arenite (primarily SiO2 with various cementing agents)
Sandstone (Quartzose)
Arenite (SiO2 principal composition)
Sandstone
Arenite (SiO2 based)
Sandstone
Arenite (Siliclastic sedimentary rock)
Conglomerate (or Breccia / Porphyry)
Clastic Sedimentary Rock (Conglomerate / Sandstone)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Chert
Silicon dioxide (SiO2)
Boxwork or Septarian Concretion
Septarian nodule / Boxwork weathering
Iron-rich breccia or weathered ironstone
Goethite–hematite-bearing limonite, possibly brecciated host rock
Rounded quartz-rich pebble
Likely quartzite or quartz-rich sandstone pebble; SiO₂-dominant
Chert (Flint variety)
Microcrystalline Silica (SiO2)
Chert (with Fossiliferous Silicification)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Chert (Jasper/Quartzite river pebble)
Microcrystalline Silica (SiO2)
Sandstone
Arenite
Fossil Shark Tooth
Chondrichthyes (class); likely Lamniformes (order) fossilized in Apatite/Hydroxyapatite
Greenstone (likely serpentinite or greenstone pebble)
Serpentinite-rich ultramafic rock; commonly dominated by serpentine-group minerals, with possible chlorite, actinolite, or magnetite
Garnet Schist
Almandine Garnet-bearing Mica Schist
Brecciated Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Shale
Lutaceous Rock (Sedimentary Mudrock)
Quartz (Chert/Chalcedony variety)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Nutting Stone / Cupstone (Sandstone or Quartzite)
Sedimentary rock with anthropogenic modification (cupule)
Chert
Chert (Microcrystalline Quartz, SiO2)
Jasper
Silicon Dioxide (SiO2) with impurities, Microcrystalline Quartz
Chalcedony
Silicon dioxide (SiO2)
Sandstone
Arenite (SiO2 primarily)
Sandstone
Sedimentary Clastic Rock (Quartz arenite)