Pearls
Pearl: biomineralized aragonite (CaCO₃) and conchiolin
gemstone
Category
Industrial Byproduct (Anthropogenic Rock Like Material)
Browse industrial byproduct (anthropogenic rock like material) specimens identified by the Rock Identifier community.
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Thunderegg (Agate or Quartz Geode)
Silica-filled rhyolitic nodule (SiO2)
sedimentary
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily Quartz with Limonite/Goethite staining)
sedimentary
Sandstone
Arenite (SiO2 predominantly)
sedimentary
Likely vertebra fossil or bone fragment
Indeterminate fossilized vertebra; mineralized hydroxyapatite, commonly Ca₅(PO₄)₃(OH)
fossil
Uncertain small pale mineral fragment
Indeterminate; possibly calcite or a light-colored feldspar fragment
mineral
Blue Sapphire
Corundum (Al2O3)
mineral
Granitic Pegmatite
Pegmatite containing Quartz, Feldspar, and Muscovite mica
igneous
Granite Pebble
Felsic Plutonic Rock (primarily Quartz, Feldspar, and Mica)
igneous
Sandstone
Arenite (primarily SiO2)
sedimentary
Epidote in Basalt
Epidotized Basalt (Ca2(Al2,Fe)(SiO4)(Si2O7)O(OH) in Mafic Igneous Host)
igneous
Pebble or Cobble (likely composed of sandstone or conglomerate)
Clastic Sedimentary Rock (specific name like sandstone, conglomerate, or breccia would require microscopic analysis of clast size and angularity)
Sedimentary Rock (possibly a conglomerate or coarse-grained sandstone)
Schist
Schist (Crystalline Metamorphic Rock)
metamorphic
Chert (or potentially Jasper/Chalcedony)
SiO2 (Silicon Dioxide)
sedimentary
Weathered quartz-rich rock fragment
Likely quartz-bearing sandstone or granitic rock; exact identification is uncertain from the image
mineral
Quartz Vein in Host Rock
Crystalline Silicon Dioxide (SiO2) in Pelitic or Shaly Matrix
metamorphic
Granodiorite (Gneissic texture)
Granodiorite (containing Quartz SiO2, Plagioclase Feldspar, and Biotite)
igneous
Conglomerate (River Rock)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Sandstone
Arenite
sedimentary
Serpentinite
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
metamorphic
Chert (Flint/Jasper variety)
Silicon Dioxide (SiO2)
sedimentary
Pumice (Basaltic/Scoria)
Vesicular Basalt / Scoria
igneous
Chert (Red Jasper variant)
Silicon dioxide (SiO2)
sedimentary
Dark river pebble, likely basalt or fine-grained volcanic rock
Basalt (probable); mostly plagioclase and pyroxene, with possible magnetite
igneous
Fossiliferous Limestone
Carbonate Sedimentary Rock (primarily CaCO3)
sedimentary
Probable amber fragment
Amber (fossilized plant resin; chiefly amorphous organic resin, commonly dominated by succinite)
gemstone
Sandstone (with potential iron mineralization)
Arenite
sedimentary
Sandstone
Sedimentary Rock (Quartz Sandstone)
sedimentary
Rough White Zircon
Zircon (Zirconium Silicate, ZrSiO4)
mineral
Gneiss
Gneiss
metamorphic
Schist
Mica Schist (Metamorphic Rock)
metamorphic
Serpentinite
Serpentinite (Mg, Fe, Ni)3Si2O5(OH)4
metamorphic
Chert (variations include Flint or Jasper)
Silicon Dioxide (SiO2)
sedimentary
Sandstone
Arenite (clastic sedimentary rock)
sedimentary
Sandstone
Sedimentary Rock (Quartz arenite)
sedimentary
Polished agate slice
Agate, a banded variety of chalcedony (microcrystalline SiO₂)
mineral
Petrified Wood
Silicified wood (primarily Silicon Dioxide, SiO2)
metamorphic
Petrified Wood
Silicified Wood (SiO2)
fossil
Sandstone
Arenite (SiO2 based)
sedimentary
Raw Diamond
Diamond (pure Carbon, C)
mineral
Chert (Red Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Quartzite Cobble
Quartzite (SiO2)
metamorphic