Black Freshwater Pearls
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Category
Browse not a natural rock specimens identified by the Rock Identifier community.
Black Freshwater Pearls
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Sodium Polyacrylate (Superabsorbent Polymer)
Sodium Polyacrylate [-CH2-CH(COONa)-]n
Lapis Lazuli
Lapis Lazuli (A complex rock primarily composed of Lazurite: (Na,Ca)8(AlSiO4)6(S,Cl,SO4,OH)2)
Amethyst
Silicon Dioxide (SiO2) with trace Iron (Fe) impurities
Amethyst
Amethyst (Silicon Dioxide with iron impurities, SiO2)
Amethyst
Amethyst (Silicon Dioxide with Iron impurities), SiO2
Unidentified Rock Fragment
Unknown
Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
Green Aventurine
Quartz (SiO2) containing Fuchsite (K(Al,Cr)2(AlSi3O10)(OH)2)
Granite
Granite (composed primarily of Quartz SiO2, Feldspar (KAlSi3O8), and Mica)
Aventurine
Silicon Dioxide (Quartz with Fuchsite inclusions) - SiO2
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium/Vanadium impurities
Ambergris
Ambra grisea (Metabolic byproduct)
Strawberry Quartz
Silicon Dioxide (SiO2) with Hematite/Goethite inclusions
Yellow Calcite
Calcium Carbonate (CaCO3)
Granite
Plutonic felsic rock (Quartz, Feldspar, Mica)
Basalt
Extrusive mafic igneous rock
Slate
Foliated Metamorphic Rock (Mainly composed of Quartz, Illite, Chlorite)
Lapis Lazuli
Na8[Al6Si6O24]S2 (Lazurite component), a rock composed primarily of Lazurite, Calcite, and Pyrite
Ironstone concretion / Limonitic Sandstone
Goethite/Hematite Cemented Sandstone (Hydrated Iron Oxide)
Gold Nugget
Native Gold (Au)
Herkimer Diamond
Quartz (Silica - SiO2)
Diamond
Diamond (Pure Carbon - C)
Polychrome Jasper
Silicon Dioxide (SiO2) with iron and other mineral inclusions
Cobaltian Calcite (Cobaltoan Calcite)
Cobalt-bearing Calcite (Ca,Co)CO3
Green Aventurine
Aventurine Quartz (SiO2 with inclusions of Fuchsite)
Diamond (Faceted)
Carbon (C) - Diamond
Libyan Desert Glass
Libyan Desert Glass (SiO2 with trace elements)
Chevron Amethyst
Silicon Dioxide (SiO2) with iron impurities
Granite
Granite (composed primarily of Quartz SiO2, Feldspar KAlSi3O8, and Mica K(Mg,Fe)3AlSi3O10(OH)2)
Pearl (Biogenic Mineral)
Calcium Carbonate (primarily Aragonite) with Conchiolin; CaCO3
Howlite
Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)
Blue Sphalerite (likely dyed or treated Druzy Quartz/Agate)
Zinc Sulfide (ZnS) or Silicon Dioxide (SiO2) with trade-name enhancement
Rough Diamond
Diamond (pure carbon / C)
Sand (Construction Grade)
Unconsolidated siliciclastic sediment (primarily SiO2)
Obsidian (Black)
Obsidian (approx. 70–75% SiO2)
Limonite (Iron Ore/Sandstone mixture)
Limonite (FeO(OH)·nH2O) often mixed with Goethite and sedimentary matrix
Rainbow Fluorite
Fluorite (Calcium Fluoride, CaF2)
Mahogany Obsidian
Volcanic glass containing Hematite or Magnetite (SiO2 + Fe2O3)
Amber
Succinite (Organic Gemstone)
Amber
Succinite (organic fossilized resin)
Obsidian
Volcanic Glass (predominantly SiO2)