Limestone
Calcium Carbonate (CaCO3)
sedimentary
Category
Synthetic (Not A Natural Rock)
Browse synthetic (not a natural rock) specimens identified by the Rock Identifier community.
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Fossiliferous Limestone
Calcareous biomicrite / Bioclastic limestone
sedimentary
Sandstone Pebble
Sandstone (Siliciclastic Sedimentary Rock)
sedimentary
Emerald in Matrix
Beryl (Be3Al2Si6O18) containing Chromium/Vanadium impurities
mineral
Sandstone
Arenite (primarily Quartz, SiO2)
sedimentary
Sandstone (likely Ferruginous)
Sandstone (SiO2 with iron oxides)
sedimentary
Sandstone (with Iron Staining)
Sandstone (mainly Quartz, SiO2, with Iron Oxides like Goethite/Hematite)
sedimentary
Green Jasper
Microcrystalline Quartz (SiO2)
sedimentary
Sandstone Pebble
Sedimentary Rock (Quartzose Sandstone)
sedimentary
Limonite (Yellow Ochre)
Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)
mineral
Turquoise (Dyed Howlite/Magnesite)
CuAl6(PO4)4(OH)8·4H2O (Natural Turquoise) or Ca2B5SiO9(OH)5 (Howlite)
mineral
Kimberlite
Kimberlite (Potassic ultramafic volcanic rock)
igneous
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
sedimentary
Shale
Shale (Argillaceous sedimentary rock)
sedimentary
Sandstone
Arenite (SiO2 with minor iron oxides)
sedimentary
Rhinestone (or glass crystal)
Silicon dioxide (if glass) / Various
Mineral/gemstone imitation
Citrine (Heat-treated Amethyst)
Citrine Quartz (SiO2)
Mineral (Tectosilicate)
Agate with Fossil/Inclusion
Silicon Dioxide (SiO2) with chalcedony and potential fossil inclusion
sedimentary
Hagstone (Adder Stone)
Chert or Sedimentary pebble with natural perforation
sedimentary
Basalt (Worn Cobble / Artifact)
Aphanitic Extrusive Igneous Rock
igneous
Quartz Veined Quartzite or Sandstone
Quartzite with Quartz Veins (SiO2)
sedimentary
Granite
Felsic intrusive igneous rock
igneous
Porphyritic Basalt or Porphyritic Andesite Pebble
Extrusive Igneous Rock
igneous
Blue Tiger's Eye
Riebeckite (crocidolite variety)
Mineral
Unidentified gray stone
Likely quartz-rich stone; exact identification is not possible from the image
mineral
Sandstone
Arenite (primarily SiO2 with various cementing agents)
sedimentary
Red Sandstone (Iron-rich)
Arenite (with Hematite cement)
sedimentary
Basalt (Greenstone/Water-worn Pebble)
Basalt (containing Chlorite/Epidote)
igneous
Sandstone
Sandstone (Quartz-rich sedimentary rock)
sedimentary
Hag Stone
Perforated Quartz / Sedimentary Rock
sedimentary
Sandstone pebble
Sandstone (Quartz-rich Arenite)
sedimentary
Smoky Quartz with Hematite inclusions
Silicon Dioxide (SiO2) with Fe2O3 inclusions
mineral
Amethyst (Purple Quartz)
Silicon Dioxide (SiO2) with iron impurities
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Sandstone (Quartzite-rich Pebble)
Arenite (primarily SiO2)
sedimentary
Sandstone
Sandstone (clastic sedimentary rock)
sedimentary
Sandstone (Quartzite-rich Cobble)
Clastic sedimentary rock (primarily SiO2)
sedimentary
Granite
Felsic intrusive igneous rock
igneous
Amethyst Elestial Quartz
Silicon Dioxide with inclusions (SiO2)
mineral
Tumbled Amethyst
Silicon Dioxide (SiO2) with iron impurities
mineral
Dyed Blue Agate Slice
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Iron Slag
Anthropogenic Vitreous Silicate (Byproduct of Smelting)
Mineral-like byproduct