Crushed Limestone and Calcite
Calcium Carbonate (CaCO3)
Category
Browse sedimentary rock (specifically a concretion or possibly a geode) specimens identified by the Rock Identifier community.
Crushed Limestone and Calcite
Calcium Carbonate (CaCO3)
Basalt
Extrusive Mafic Igneous Rock
Basalt
Basalt
Sandstone (likely Arkosic)
Clastic Sedimentary Rock (primarily SiO2 with Feldspar)
Sandstone (Pebble)
Arenite / Clastic Sedimentary Rock
Sandstone
Clastic sedimentary rock (primarily SiO2)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Pumice
Pumice (a highly vesicular volcanic glass)
Basalt
Mafic Igneous Rock (composed primarily of Pyroxene and Plagioclase Feldspar)
Sandstone
Arenite (SiO2 based)
Andesite
Andesite (Intermediate Extrusive Volcanic Rock)
Sandstone (likely Quartzose Sandstone)
Arenite (primarily SiO2)
Sandstone
Arenite (composed primarily of SiO2)
Slag
Anthropogenic Vitrophyre (Iron or Smelting Slag)
River Pebble (Quartz/Jasper)
Silicon Dioxide (SiO2)
Sandstone (with potential Arkose/Lithic characteristics)
Arenite (Sedimentary rock composed of sand-sized grains)
Sandstone (Quartzose)
Arenite (composed primarily of SiO2)
Andesite Porphyry
Andesite (Intermediate Volcanic Rock)
Basalt River Pebble
Mafic volcanic rock (Basalt)
Basalt
Extrusive mafic igneous rock
Basalt
Extrusive mafic igneous rock
Basalt
Extrusive mafic igneous rock
Diorite
Intermediate plutonic igneous rock
Pumice
Pumice (Vesicular volcanic glass)
Basalt River Rock
Basalt (Aphanitic Mafic Igneous Rock)
Granite
Granite (Phaneritic intrusive igneous rock)
Chert (Iron-Stained)
Microcrystalline Silica (SiO2)
Sandstone (likely Arkose or Quartz Sandstone)
Arenite (SiO2 + varied clasts)
Basalt
Mafic Volcanic Rock (composed mainly of Plagioclase, Pyroxene, and Olivine)
Sandstone (Calcareous Sandstone)
Calcareous Sandstone (primarily SiO2 with CaCO3 cement)
Granite
Granite (a plutonic igneous rock composed of quartz, feldspar, and mica)
Chert (Chert Nodule with Chalky Cortex)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Sandstone
Arenite (Clastic Sedimentary Rock)
Sandstone (Pet Rock)
Clastic sedimentary rock (primarily SiO2)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Limonite (Iron Ore)
Limonite (unstructured hydrated iron(III) oxide-hydroxides, often FeO(OH)·nH2O)
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Red Sandstone
Arenite (primarily Quartz and Feldspar with Iron Oxide cement)
Shale or Mudstone (Based on appearance)
Shale (fine-grained, laminated fissile sedimentary rock) / Mudstone (fine-grained, non-fissile sedimentary rock)
Milky Quartz
Silicon Dioxide (SiO2)
Chert / Flint
Chert (Cryptocrystalline Silica, SiO2)
Chert (Field Stone/Pebble)
Microcrystalline or cryptocrystalline Quartz (SiO2)