Sandstone
Arenite (predominantly Quartz Sandstone)
Category
Browse organic structure (not a rock) specimens identified by the Rock Identifier community.
Sandstone
Arenite (predominantly Quartz Sandstone)
Unakite
Epidotized Granite (SiO2 with Ca2(Al,Fe)3(SiO4)3(OH))
Basalt Pebble
Basalt (Mafic Extrusive Igneous Rock)
Sandstone
Arenite (primarily SiO2)
Pearl (nacre)
Calcium Carbonate (mostly CaCO3 as Aragonite) and Conchiolin
Pearl (Imitation or Cultured)
Calcium Carbonate (Aragonite/Calcite) - CaCO3
Sandstone (likely Quartzose Sandstone)
Clastic Sedimentary Rock (primarily SiO2)
Granite featuring Quartz Vein
Granite with hydrothermal silica (SiO2) intrusion
Jasper with Quartz inclusions
Silicon Dioxide (SiO2) with impurities
Mixed Tumbled Gemstones and River Rocks
Mixed Decorative Stones (predominantly Silicon Dioxide - SiO2 variants)
Sandstone (with Lichen)
Arenite (composed primarily of SiO2)
Scoria (with likely iron oxidation)
Scoria (Basaltic Scoria)
Sandstone (with Iron Staining)
Clastic sedimentary rock (SiO2 with Fe2O3 impurities)
Sandstone (Weathered)
Arenite (primarily SiO2)
Rose Quartz
Silicon Dioxide (SiO2) with trace amounts of titanium, iron, or manganese
Sandstone (likely Arkose or Quartz Sandstone)
Arenite (SiO2 + varied clasts)
Coquina
Bioclastic Limestone (composed primarily of CaCO3)
Amber
Fossilized Tree Resin (Amorphous Hydrocarbon)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Quartzite Pebble (River Rock)
Quartzite (mainly SiO2)
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)
Gastropod Steinkern (Internal Mold Fossil)
Gastropoda (Class); Internal mold or 'Steinkern' composed of Calcium Carbonate (CaCO3) or Sedimentary matrix
Grey Granite
Phaneritic Felsic Igneous Rock (primarily Quartz, Feldspar, and Mica)
Pink Granite
Phaneritic Felsic Intrusive Igneous Rock
Basalt (Vesicular)
Vesicular Basalt
Diorite (Salt and Pepper Rock)
Diorite
Crinaudite / Fossilized Crinoid Stem
Crinoid (Echinodermata) in a Calcitic/Siliceous Matrix
Granite
Phaneritic Felsic Igneous Rock (Granite)
Mookaite Jasper
Silicified Radiolarite (SiO2)
Andesite
Andesite (Intermediate Volcanic Rock)
Pink Granite
Granite (Phaneritic intrusive rock)
Snowflake Obsidian
Spherulitic Volcanic Glass (primarily SiO2 with Cristobalite inclusions)
Quartz Vein in Host Rock (Gabbro or Basalt)
Silicon Dioxide (SiO2) with Mafic Silicates
Chert / Flint
Cryptocrystalline quartz (SiO2)
Pearl (Cultured or Natural)
Aragonite (CaCO3) with Conchiolin
Dog (Sleeping)
Canis familiaris (or Canis lupus familiaris)
Scoria
Extrusive Basaltic Scoria
Granite Cobble
Plutonic Igneous Rock (Granitic)
Jasper with Quartz Veining
Silicon Dioxide (SiO2) - Opaque cryptocrystalline variety of Quartz
Ambergris
Ambrein (C30H52O Derivative)
Basalt
Extrusive mafic igneous rock
Amber (Cherry Amber)
Succinite (C10H16O)