Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
Category
Synthetic (Man Made Glass)
Browse synthetic (man made glass) specimens identified by the Rock Identifier community.
Learn about Synthetic (Man Made Glass) in the encyclopedia
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Banded Calcite (often commercially sold as 'Mexican Onyx' or 'Honey Onyx')
Calcite (Calcium Carbonate, CaCO3)
sedimentary
Amethyst
Amethyst (Silicon Dioxide, SiO2 + Fe4+ impurities)
mineral
Chert / Flint
Chert (varieties include Flint)
Sedimentary
Ferrous Slag (Iron Smelting By-product)
Fused Siliceous Slag
Anthropogenic Material (Man-made Rock)
Ferrochrome Slag
Industrial Glassy Slag (Fe-Cr alloy byproduct)
Antropogenic (Man-made industrial byproduct)
Asphalt Concrete
Bituminous Concrete / Asphaltic Composite
not a natural rock (man-made composite)
Brecciated jasper (likely red-and-cream jasper)
Jasper, an opaque microcrystalline variety of quartz; primarily cryptocrystalline SiO₂ with iron-oxide staining and possible chalcedony/quartz veining
gemstone
Banded Sandstone
Arenite with Liesegang banding
sedimentary
Rose Gold (Copper-Gold Alloy)
Aurum-Cuprum Alloy (Au-Cu)
mineral (native element alloy)
Fossilized Ray Barb (Stinger) Fragment
Myliobatiformes indet. (Fossil stingray spine)
fossil
Diamond
Carbon (C)
gemstone
Diorite
Intermediate plutonic igneous rock
igneous
Diamond
Carbon (C)
gemstone
Flint
Silicon Dioxide (SiO2) - Microcrystalline Quartz / Chert
sedimentary
Diamond
Natural Diamond (Carbon, C)
gemstone
Dyed Quartz (imitating Emerald/Green Quartz)
Silicon Dioxide (SiO2) with artificial pigment
mineral
Gold
Native Gold (Au)
mineral
Smoky Quartz
Silicon Dioxide (SiO2) with aluminum impurities
mineral
White Marble
Recrystallized Calcite Rock (CaCO3)
metamorphic
Diorite (River Pebble)
Intermediate Phaneritic Igneous Rock
igneous
Dolerite (Diabase)
Dolerite / Diabase
igneous
Amazonite
KAlSi3O8 (Potassium Aluminum Silicate)
mineral
Black Tourmaline
Schorl (Na(Fe²⁺)₃Al₆(BO₃)₃Si₆O₁₈(OH)₄)
mineral
Coral Rock (Coquina)
Biogenic Limestone (Calcium Carbonate - CaCO3)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Pyrite
Iron Disulfide (FeS2)
mineral
Chert (Jasper/Agate variety)
Silicon Dioxide (SiO2)
sedimentary
Banded Calcite (often sold as 'Mexican Onyx' or 'Green Onyx')
Calcite (Calcium Carbonate, CaCO3)
Sedimentary
Moonstone
Orthoclase Feldspar (formula: (K,Na)AlSi3O8)
mineral
Diamond (as set in a metal alloy ring)
Diamond (Pure Carbon, C)
mineral
Fossilized Shark Tooth
Carcharocles sp. or Striatolamia sp. (Phosphate/Carbonate mineralized Hydroxyapatite)
sedimentary
Grey Granite
Phaneritic Felsic Intrusive Igneous Rock
igneous
Pearl (Biogenic)
Nacre / Calcium Carbonate (CaCO3)
mineral
Sunstone
Aventurine Feldspar (Plagioclase Feldspar with inclusions)
mineral
Diamond
Carbon (C)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Chert (Jasper Variant likely)
Silicon Dioxide (SiO2)
Sedimentary Rock or Mineral (depending on origin and purity)
Granite
Phaneritic Igneous Rock (composed mostly of Quartz, Alkali Feldspar, and Plagioclase)
igneous
Granite
Phaneritic plutonic rock (SiO2 typically >69%)
igneous
Muscovite Mica
Muscovite (Potassium Aluminum Silicate Hydroxide Fluoride), KAl2(AlSi3O10)(OH,F)2
mineral
Tree Agate
Chalcedony (SiO2)
gemstone