Pearl
Aragonite / Calcium Carbonate (CaCO3)
mineraloid
Category
Anthropogenic (Man Made Industrial Byproduct)
Browse anthropogenic (man made industrial byproduct) specimens identified by the Rock Identifier community.
Learn about Anthropogenic (Man Made Industrial Byproduct) in the encyclopedia
View all →
Marble
Marble (primarily Calcite, CaCO3 or Dolomite, CaMg(CO3)2)
Metamorphic Rock
Sandstone
Arenite (SiO2 composition dominant)
sedimentary
Basalt with Secondary Mineralization (Likely Zeolites or Calcite)
Aphanitic mafic volcanic rock with secondary mineral inclusions (e.g., CaAl2Si3O10·3H2O for Scolecite)
igneous
Red gemstone ring, likely garnet or synthetic ruby
Possibly almandine garnet (Fe₃Al₂(SiO₄)₃) or corundum/ruby (Al₂O₃); image alone cannot distinguish
gemstone
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Chert (Flint)
Silicon Dioxide (SiO2)
sedimentary
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Chalk
Micrite (primarily Calcium Carbonate or CaCO3)
sedimentary
Pearl
Organic gemstone (Calcium carbonate - CaCO3)
mineral
Chert (variations include Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
sedimentary
Sandstone
Arenite (SiO2, often with CaCO3 or Fe2O3 cement)
sedimentary
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Red Quartzite
Quartzite (Metamorphosed Quartz Arenite)
metamorphic
Quartzite
Metamorphic Quartz Rock (SiO2)
metamorphic
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Sandstone (Quartzose)
Sandstone (SiO2 dominated)
sedimentary
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Quartzite
Metamorphic Quartzite (primarily SiO2)
metamorphic
Quartzite
Metamorphic Quartzite (primarily SiO2)
metamorphic
Sandstone
Arenite
sedimentary
Rough amber-like brown mineral specimen
Uncertain from photograph; possibly iron-stained quartz, common opal, or resinous amber
mineral
Vesicular volcanic rock, likely weathered pumice or scoria
Pumice/scoria; predominantly volcanic glass and feldspar, with possible iron oxides
igneous
Sandstone
Arenite (primarily SiO2)
sedimentary
Amethyst
Quartz (SiO2) with trace iron impurities
Mineral
Sandstone
Clastic Sedimentary Rock
sedimentary
Quartzite
Metamorphic Quartzite
metamorphic
Chert (varietal: Flint/Jasper)
Silicon Dioxide (SiO2)
sedimentary
Fossilized Shell in Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Sandstone (Quartzose)
Arenite (primarily SiO2)
sedimentary
Basalt
Basalt (Mafic volcanic rock)
igneous
Likely metallic meteorite fragment
Unclassified iron-rich meteorite; possible stony-iron or iron meteorite
meteorite
Diamond
Carbon (C)
mineral
Quartzite
Quartzite (Metamorphosed Sandstone)
metamorphic
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Diamond
Carbon (C)
gemstone
Sapphire (likely blue synthetic sapphire or blue glass in a ring)
Corundum (Al₂O₃), specifically the blue variety due to trace amounts of iron and titanium impurities. If synthetic, it would still be Al₂O₃.
Mineral
Chert (Siltstone / Flint)
SiO2 (Cryptocrystalline Quartz)
sedimentary
Sandstone
Sedimentary Rock (Quartz Sandstone)
sedimentary