Amazonite
KAlSi3O8 (Potassium Aluminum Silicate)
Category
Browse not a rock (man made origin) specimens identified by the Rock Identifier community.
Amazonite
KAlSi3O8 (Potassium Aluminum Silicate)
Quartz Pebble
Silicon Dioxide (SiO2)
Peridot
Olivine (Mg,Fe)2SiO4
Crazy Lace Agate
Silicon dioxide (SiO2) - a variety of banded Chalcedony (cryptocrystalline quartz)
Obsidian
Volcanic Glass (Amorphous SiO2)
Amethyst
Silicon Dioxide (SiO2) with Fe3+ impurities
Malachite
Malachite (Copper Carbonate Hydroxide) - Cu2CO3(OH)2
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
Pyrulite (Pyrite / Chalcopyrite)
Iron Sulfide (FeS2) or Copper Iron Sulfide (CuFeS2)
Specular Hematite (Specularite)
Iron Oxide (Fe2O3)
Peridot
Olivine (specifically, the gem-quality variety forsterite, (Mg,Fe)2SiO4)
Synthetic Blue Aura Quartz
Silicon Dioxide (SiO2) with Metallic Infusion
Ferrochrome Slag
Industrial Glassy Slag (Fe-Cr alloy byproduct)
Sea Glass (Kelly Green)
Amorphous Silica (Silicon Dioxide with Iron/Chromium additives)
Synthetic Costume Glove (Paws)
Polyethylene terephthalate (Polyester) & Polyurethane blend
Slag
Anthropogenic Vitrification Product / Silicate Slag
Chert (Iron-stained)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Tan/Brown variety)
Chert (Silicon Dioxide, SiO2)
Chert (Nodule)
Chert (SiO2)
Coquina
Biogenic Limestone (Calcite/Aragonite base, CaCO3)
Amber
Succinite (Carbon-based organic compound; approximate formula C10H16O)
Chert (and/or Flint)
Chert (Cryptocrystalline variety of Quartz, SiO2)
Chert (and Flint)
Silicon Dioxide (SiO2)
Chert (specifically White Chert or Novaculite)
Silicon Dioxide (SiO₂)
Flint
Chert (a form of cryptocrystalline quartz, chemical formula SiO₂)
Rose Gold (Copper-Gold Alloy)
Aurum-Cuprum Alloy (Au-Cu)
Chalk
Calcium Carbonate (CaCO3)
Chert (Flinty variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Chert (and associated river cobbles)
Silicon dioxide (SiO2)
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Banded Calcite (often commercially sold as 'Mexican Onyx' or 'Honey Onyx')
Calcite (Calcium Carbonate, CaCO3)
Chert (varieties include Flint and Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Amethyst
Amethyst (Silicon Dioxide, SiO2 + Fe4+ impurities)
Epidote (or Epidote-rich rock)
Epidote. Mineral formula: Ca2(Al,Fe)3(SiO4)3(OH).
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Pyrite
Iron Sulfide (FeS2)
Chert (variations include Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sapphire
Corundum (Al2O3)
Green Slag Glass
Amorphous Silica / Glassy Blast Furnace Slag
Turquoise
Hydrated phosphate of copper and aluminium [CuAl6(PO4)4(OH)8·4H2O]
Moonstone
Orthoclase Feldspar (formula: (K,Na)AlSi3O8)