Fossilized Coral (Petoskey-style)
Hexagonaria percarinata (Fossilized Rugose Coral)
sedimentary
Category
Mineraloid (Man Made Glass)
Browse mineraloid (man made glass) specimens identified by the Rock Identifier community.
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Diorite (River Pebble)
Intermediate plutonic igneous rock
igneous
Diorite
Diorite (Intermediate intrusive igneous rock)
igneous
Yellow Chert (Chalcedony)
Microcrystalline Quartz (SiO2)
sedimentary
Bituminous Coal (with Anthracite or Vitrinite inclusion)
Organic-rich Sedimentary Rock (Carboniferous classification)
sedimentary
Dyed Blue Agate Slice
Silicon Dioxide (SiO2)
mineral
Tumbled Gabbro
Gabbro (Mafic intrusive igneous rock)
igneous
Chert
Microcrystalline Quartz (SiO2)
sedimentary
Fossilized Bored Limestone
Limestone with Ichnofossils (Gastrochaenolites or Entobia)
sedimentary
Chert (Iron-stained)
Chert (Microcrystalline and Cryptocrystalline Quartz, SiO2)
sedimentary
Diamond in Kimberlite
Diamond (C in Kimberlite Matrix)
igneous
Chalk
Calcium Carbonate (CaCO3)
sedimentary
Desert Rose (also known as Sand Rose)
Gypsum (CaSO4·2H2O) or Barite (BaSO4) with sand inclusions
mineral
Dragon Vein Agate (Dyed/Treated)
Agate (SiO2)
mineral
Crinoid Fossil Stem Segment
Class Crinoidea (Echinodermata)
sedimentary
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
mineral
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)
Synthetic Blue Aura Quartz
Silicon Dioxide (SiO2) with Metallic Infusion
mineral (synthetic/man-made coating)
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)
Synthetic Costume Glove (Paws)
Polyethylene terephthalate (Polyester) & Polyurethane blend
Non-geological / Man-made textile
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
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
Coral Rock (Coquina)
Biogenic Limestone (Calcium Carbonate - CaCO3)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Pyrite
Iron Disulfide (FeS2)
mineral