Pumice
Pumice (a volcanic glass, primarily SiO2 with Al2O3)
Category
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Pumice
Pumice (a volcanic glass, primarily SiO2 with Al2O3)
Bivalve Fossil (Clam)
Class Bivalvia (Calcium Carbonate, CaCO3)
White Quartz Pebble
Silicon Dioxide (SiO2)
Chert (varieties include Flint and Jasper)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Common Opal in Host Rock
Hydrated Silica (SiO2·nH2O)
Botryoidal Chalcedony (Desert Rose / Agate)
Silicon Dioxide (SiO₂)
Sandstone (Pebble)
Arenite (primarily SiO2)
Basalt
Basalt (dominated by plagioclase feldspar and pyroxene)
Chert (Agatized)
Silicon dioxide (SiO2)
Chert (Jasper)
Silicon Dioxide (SiO2)
Carnelian
Carnelian (Silicon Dioxide - SiO2)
Carnelian (Chalcedony)
Silicon Dioxide (SiO2)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Sandstone (Quartzose Sandstone)
Clastic sedimentary rock (primarily SiO2)
Limestone
Calcium Carbonate (CaCO3)
Sandstone (with Iron Staining)
Clastic Sedimentary Rock (primarily Quartz, SiO2)
Sandstone
Arenite
Basalt
Basalt (Aphanitic Mafic Volcanic Rock)
Sandstone
Arenite (primarily SiO2)
Sandstone
Arenite (primarily SiO2)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Porphyritic Basalt
Porphyritic Basalt (Mafic extrusive rock)
Andesite
Andesite (Intermediate Extrusive Igneous Rock)
Quartz on Matrix
Silicon Dioxide (SiO2)
Red Jasper (Quartz)
Silicon Dioxide (SiO2) with Iron impurities
Sandstone
Arenite (SiO2 based with primary clasts 0.0625 to 2 mm)
Sandstone
Arenite (primarily SiO2)
Mookaite Jasper
Silicified Radiolarite (SiO2)
Sandstone (Ferruginous)
Arenite (Fe-rich)
Sandstone (with potential trace fossils)
Clastic sedimentary rock (primarily SiO2)
Collection of Minerals and Ores
Various (e.g., Uraninite (U3O8), Carbon (C), Native Gold (Au), Hematite (Fe2O3), Galena (PbS), etc.)
Chert (specifically Yellow/Common Opal or Jasper mixture)
Silicon Dioxide (SiO2)
Chert (specifically Yellow/Honey Jasper variety)
Cryptocrystalline Quartz (SiO2)
Sandstone
Arenite (primarily SiO2)
Sandstone (Gneissic or Banded)
Clastic Sedimentary Rock (composed predominantly of SiO2)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Basalt
Extrusive Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)
Sandstone (likely Arkosic or Quartzose)
Arenite (SiO2 based with mineral inclusions)
Manganese Oxide Crust on Limestone
Manganese Oxides (e.g., Pyrolusite MnO2 or Romanechite) on CaCO3
Sandstone
Arenite (primarily SiO2)
Ammonite Fossil
Ammonoidea (subclass)