Ferruginous Sandstone (River Pebble)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 cement)
Category
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Ferruginous Sandstone (River Pebble)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 cement)
Carnelian (Red Chalcedony)
Silicon Dioxide (SiO2) - variety of Chalcedony
Agate
Chalcedony (cryptocrystalline variety of Quartz, SiO2)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of Manganese or Iron oxides
Yellow Chalcedony
Silicon Dioxide (SiO2)
Banded Gneiss with Quartz Vein
Foliated Metamorphic Rock (Gneiss)
Pumice (likely)
Pumice (extrusive igneous rock)
Chert (Common Opal variant)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Sandstone
Arenite (SiO2 principal)
Chalcedony (Common Agate)
Silicon Dioxide (SiO2)
Banded Gneiss
Gneiss (Metamorphic Rock)
Greenstone / Diabase Porphyry
Porphyritic Diabase (Micro-gabbro)
Sandstone (with cross-bedding)
Arenite (composed primarily of Quartz: SiO2)
Sandstone (Greywacke/Lithic Sandstone)
Arenite (composed primarily of SiO2)
Mica Schist
Mica Schist (KAl2(AlSi3O10)(OH)2 - Muscovite component)
Common Opal with Host Rock
Opal (Hydrated silica, SiO2·nH2O)
Quartz Vein in Host Rock (Likely Slate or Shale)
Hydrothermal Quartz (SiO2) in Pelitic host rock
Gneiss
Gneiss
Gneiss
Gneiss
Almandine Garnet in Schist
Almandine, Fe3Al2(SiO4)3
Sandstone
Arenite (composed primarily of Quartz: SiO2)
Quartz (Milky Quartz)
Silicon Dioxide (SiO₂)
Herkimer Diamond
Quartz (Silicon Dioxide, SiO2)
Banded Agate (Tumbled)
Cryptocrystalline Quartz (SiO2)
Milky Quartz (Vein Quartz)
Silicon Dioxide (SiO2)
Carnelian Agate
Carnelian (Silicon Dioxide: SiO2)
Slate
Foliated Metamorphic Rock (composed primarily of Quartz, Muscovite, and Illite)
Quartz (Iron-Stained)
Silicon Dioxide (SiO2)
Opal
Hydrated Silica (SiO2·nH2O)
Quartz / Rock Crystal
Silicon Dioxide (SiO2)
Kambaba Jasper
Stromatolite / Fossilized Algae (Rhyolitic structure)
Marble
Marble (metamorphosed limestone or dolostone), primarily composed of calcite (CaCO3) or dolomite (CaMg(CO3)2)
Milky Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
Grey River Stone (Gneiss/Schist mix)
Foliated Metamorphic Rock (variable mineral formula)
Sandstone (with Iron Staining)
Arenite (composed primarily of SiO2 with Fe2O3 staining)
Schist
Chlorite/Mica Schist
Granite
Granite (a common igneous rock)
Black Mountain Stone (Seiryu Stone)
Limestone with Calcite veins (CaCO3)
River Rock (Greywacke/Sandstone)
Lithic Wacke
Dalmatian Stone
Dalmatian Jasper (Aplitic Perthite)