Mineraloid (Human Made Geological Specimen)

Browse mineraloid (human made geological specimen) specimens identified by the Rock Identifier community.

Conglomerate

Conglomerate (Sedimentary rock containing rounded clasts)

sedimentary

Pearls

Aragonite (calcium carbonate) and Conchiolin

Mineraloid

Chert (Yellow Jasper/Flint)

Microcrystalline Quartz (SiO2)

sedimentary

Quartzite Arrowhead (Archaeological Lithic)

Recrystallized Quartz (SiO2)

metamorphic

Smoky Quartz

Smoky Quartz (SiO2)

mineral

Sandstone (Pebble)

Sandstone (arenite, arkose, wacke depending on composition)

sedimentary

Dyed Dragon Vein Agate

Silicon Dioxide (SiO2) with artificial pigment

mineral

Sandstone (Ferruginous)

Arenite (SiO2 with Fe2O3 inclusions)

sedimentary

Jasper Marble

Silicon Dioxide (SiO2) with Impurities

sedimentary

Granite

Granite (Phaneritic Quartz-Feldspar intrusive rock)

Igneous

Amber (Black)

Amber (succinite, retinite, etc., specifically, heavily included/dark varieties)

Mineraloid

Asphalt / Road Aggregate

Bituminous Conglomerate (synthetic)

sedimentary

Sea Glass (specifically Frosted White)

Amorphous Silica (substance: Sodium-calcium silicate glass)

Mineraloid (Anthropogenic/Man-made rock)

Chert

Chert (microcrystalline quartz, SiO2)

sedimentary

Artificial Rock Face (Faux Rock)

Glass Fiber Reinforced Concrete (GFRC)

man-made/construction material

Chert Pebble (Jasper variety)

Microcrystalline Quartz (SiO2)

sedimentary

Obsidian

Volcanic Glass (SiO2 + impurities)

igneous

Halite

Halite (Sodium Chloride, NaCl)

mineral

Obsidian

Obsidian (Extrusive Volcanic Glass)

igneous

Diabase (Greenstone)

Diabase (Dolerite)

igneous

Blue Goldstone

Synthetic Avanturine Glass (or Aventurine Glass)

Synthetic Glass

Obsidian

Obsidian (Volcanic Glass)

igneous

Red Jasper

Silicon Dioxide (SiO2) with Hematite (Fe2O3)

sedimentary

Chert (Yellow Jasper variant)

Silicon Dioxide (SiO2)

sedimentary

Sandstone (specifically Arkose or Quartz Arenite)

Arenite (primarily SiO2 with possible Feldspar)

sedimentary

Obsidian (Black Obsidian)

Obsidian (Volcanic Glass)

igneous

Chert (Flint/Jasper variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

sedimentary

Concrete with Exposed Aggregate

Anthropogenic conglomerate (Concrete)

man-made rock (sedimentary analogue)

Pearl

Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3

mineral

Obsidian

Volcanic Glass (predominantly SiO2, approximately 70% or more)

igneous

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

sedimentary

Opalite (a synthetic glass)

Silicon Dioxide (SiO2) with various additives; not a true mineral but a man-made gem simulant

Mineral Simulant (Synthetic Glass)

Fossilized Coral (Coquina/Limestone)

Cnidaria Anthozoa (Fossilized)

sedimentary

Petrified Wood (Silicified Wood)

Silicified Paleoflora (mainly Quartz, SiO2)

metamorphic

Metal Alloy (Jewelry)

Not a naturally occurring rock or mineral; likely a metal alloy for jewelry. Possible compositions include sterling silver (92.5% silver, 7.5% copper), or other silver/gold alloys.

Man-made Material (jewelry, metal alloy)

Bog Iron / Limonite Concretion

Goethite/Limonite mixture (FeO(OH)·nH2O)

sedimentary

The user-provided image does not contain a rock or mineral specimen

N/A

Iron Ore / Ironstone Concretion

Mixture of iron oxide/hydroxide minerals, likely some combination of Hematite (Fe2O3), Goethite (α-FeOOH), and Limonite (a general term for hydrated iron oxides of variable composition) or potentially Bauxite (a mixture of aluminum hydroxides, often with iron oxides, (Al(OH)3) and FeO(OH)). The visual characteristics strongly suggest iron-rich material.

Mineral, specifically an iron ore