Sandstone Concretion
Sedimentary concretion
Sedimentary
Category
Man Made Material (Constructed)
Browse man made material (constructed) specimens identified by the Rock Identifier community.
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Blue Lace Agate
Chalcedony (SiO2) with trace inclusions
mineral
Sandstone (Water-worn Cobble)
Arenite (SiO2 with CaCO3 or Fe2O3 cement)
sedimentary
Turquoise
Hydrous phosphate of copper and aluminium (CuAl6(PO4)4(OH)8·4H2O)
gemstone
Fossilized echinoid (sea urchin), likely a flint/chalk-associated test
Echinoid fossil; likely a regular echinoid such as Echinocidaris or related taxon, composed mainly of recrystallized calcite (CaCO₃)
fossil
Diabase (Dolerite)
Diabase / Dolerite
igneous
Land Snail Shell
Gastropoda (Calcium Carbonate, CaCO3)
fossil
Goldstone (aventurine glass)
Synthetic copper-bearing soda-lime glass; commonly sold as red goldstone
gemstone
Pearl
Biogenic CaCO3 (Aragonite and Calcite)
mineral
Flint
SiO2 (Cryptocrystalline Quartz)
sedimentary
Chert (Flint / Quartz Nodule)
Microcrystalline Quartz (SiO2)
sedimentary
Gypsum (Satin Spar / Alabaster variety)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
mineral
Pearl (Biogenic Mineraloid)
Calcium carbonate (CaCO3) primarily as Aragonite
mineral
Granite
Plutonic Igneous Rock (composed typically of SiO2, Al2O3, K2O, Na2O, CaO)
igneous
Lava Rock (Dyed)
Basalt / Volcanic scoria
igneous
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
sedimentary
Chert Pebble/Nodule
Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)
Sedimentary
Siltstone Pebble
Siltstone (composed of microscopic quartz and clay minerals)
sedimentary
Beaded Jewelry (Assorted Gemstones)
Various minerals, including but not limited to Quartz (SiO2), Garnet (X3Y2(SiO4)3), Jade (Na(Al,Fe)Si2O6), Amethyst (SiO2),等の多様な組み合わせ
Mineral, Jewelry
Tumbled sodalite with white calcite veining
Sodalite, Na8(Al6Si6O24)Cl2, commonly intergrown with calcite, CaCO3
mineral
Diamond (or Cubic Zirconia)
Carbon (C) or Zirconium Dioxide (ZrO2)
gemstone
Vesicular Basalt (or Scoria)
Vesicular Basalt
igneous
Belemnoit (Fossil)
Belemnoidea (Order), Rostrum / Guard
sedimentary
Gold (Elemental Metal)
Gold (Au)
Mineral
Chalk
CaCO3 (primarily Calcium Carbonate), biogenic sedimentary rock
Sedimentary
Granite
Phaneritic Plutonic Felsic Rock
igneous
Granite
Granite (Phaneritic igneous rock)
igneous
Granite
Phaneritic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Tumbled brown chalcedony (likely jasper or agate)
Microcrystalline quartz, SiO₂; chalcedony with iron-oxide staining
mineral
Diamond
Carbon (C)
mineral
Rutilated Quartz
Silicon Dioxide (SiO2) with Titanium Dioxide (TiO2) inclusions
mineral
Granodiorite
Intrusive Igneous Rock
igneous
Diamond
Diamond (pure carbon C)
mineral
Pearl
Calcium Carbonate (CaCO3) - Aragonite/Calcite
mineral
Turquoise
Turquoise, CuAl6(PO4)4(OH)8·4H2O
mineral
Diamond
Cubic carbon (C)
mineral
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Quartzite
Metamorphic Quartzite (SiO2)
metamorphic
Quartzite
Metamorphic Quartzite (primarily SiO2)
metamorphic
Quartzite
Metamorphic Quartzite (primarily SiO2)
metamorphic