Sandstone (likely Siltstone)
Arenite or Siltstone (high SiO2 content)
Category
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Sandstone (likely Siltstone)
Arenite or Siltstone (high SiO2 content)
Scoria (Lava Rock)
Vesicular Basalt / Scoria
Sandstone (Quartzite texture)
Arenite (SiO2 secondary)
Sandstone (Ferruginous)
Sandstone (primarily SiO2 with Fe2O3 cement)
Sand Dollar Fossil
Echinoidea (Clypeasteroida)
Chert (specifically Flint or Common Opal variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sandstone (likely Quartzose Sandstone)
Arenite (composed primarily of SiO2)
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 cement)
Granite
Phaneritic Intrusive Igneous Rock (Granite)
Pumice
Vesicular Rhyolite / Pumice
Basalt River Pebble
Basalt (Mafic Extrusive Volcanic Rock)
Sandstone (Ferruginous)
Arenite with Iron Oxide matrix
Sandstone
Arenite (SiO2 primarily)
Dalmatian Jasper
Dalmatian Stone (a microcrystalline quartz and feldspar rock with arfvedsonite)
Basalt
Mafic Extrusive Igneous Rock
Basalt (River Cobble)
Basalt (Mafic volcanic rock)
Basalt
Basalt (Mafic volcanic rock)
Basalt
Basalt (Mafic volcanic rock)
Basalt
Extrusive mafic igneous rock
Sandstone (Ferruginous)
Arenite (primarily SiO2 with iron oxide cement)
Sandstone (likely Quartzose Sandstone)
Clastic Sedimentary Rock (primarily SiO2)
Sandstone (Pebble)
Arenite (primarily SiO2)
Basalt River Cobble
Basalt (Aphanitic Mafic Volcanic Rock)
Basalt
Basalt (Mafic Extrusive Igneous Rock)
Gabbro
Gabbro (phaneritic mafic intrusive rock)
Red Jasper
Jasper (a variety of Chalcedony, SiO₂ with impurities)
Basalt with Peridotite Inclusion
Mafic Volcanic Rock (Extrusive Igneous) with Ultramafic Xenolith
Pumice
Pumicite
Sandstone (lithic wacke/arenite)
Clastic sedimentary rock (primarily SiO2)
Chalcedony (Agate)
Silicon Dioxide (SiO2)
Chert (specifically Red Chert or Jasper)
Microcrystalline Quartz (SiO2)
Sandstone
Arenite (SiO2 primarily)
Conglomerate
Clastic sedimentary conglomerate
Sandstone
Arenite (composed primarily of SiO2)
Conglomerate
Conglomerate (Clastic Sedimentary Rock)
Limestone (Weathered Aggregate)
Sedimentary Carbonate Rock (CaCO3)
Sandstone
Arenite (Siliclastic sedimentary rock)
Sandstone (Greywacke)
Clastic Sedimentary Rock (SiO2 with lithic fragments)
Sandstone (with potential iron-oxide weathering)
Arenite (SiO2 based)
Sandstone
Arenite (primarily SiO2)
Chert (specifically Flint or Dark Chert)
Chert (SiO2)
Sandstone (with minor quartz and possible clay components)
Clastic Sedimentary Rock (SiO2 dominated)