Crushed Limestone and Calcite
Calcium Carbonate (CaCO3)
sedimentary
Category
Man Made Object (Ring)
Browse man made object (ring) specimens identified by the Rock Identifier community.
Crinoid Fossil in Limestone
Crinoid (Class Crinoidea) in Fossiliferous Limestone (CaCO3)
sedimentary
Granite
Granite (Felsic Plutonic Rock)
igneous
Rose Quartz
Silicon Dioxide (SiO2) with trace Titanium, Manganese, or Iron
mineral
Basalt
Basalt (composition predominately plagioclase feldspar and pyroxene)
igneous
Sandstone (likely Ferruginous)
Sandstone (SiO2 with iron oxides)
sedimentary
Quartz
Silicon Dioxide (SiO2)
Mineral
Chert (specifically Flint or Jasper-Chert)
Silicon Dioxide (SiO2)
sedimentary
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Nephrite Jade
Ca2(Mg,Fe)5Si8O22(OH)2
metamorphic
Moonstone (specifically White Moonstone or Girasol Quartz)
Potassium aluminum silicate (KAlSi3O8)
mineral
Sandstone
Sandstone (clastic sedimentary rock)
Rock
Banded Gneiss
Gneiss (pronounced 'nice')
metamorphic
Chert (Flint)
Microcrystalline Quartz (SiO2)
sedimentary
Chert (Jasper)
Microcrystalline Quartz (SiO2)
sedimentary
Pyrite
Pyrite (FeS2)
Mineral
Quartz (likely milky quartz or a stained variety)
Silicon Dioxide (SiO₂)
Mineral
Schist
Schist (various mineral compositions)
Metamorphic
Nephrite Jade
Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)
metamorphic
Fossil Coral
Coral Limestone (a type of biogenic sedimentary rock)
Sedimentary
Labradorite (likely Black Labradorite or Larvikite)
Labradorite (Na,Ca)(Al,Si)4O8. If a rock, it is typically anorthosite, gabbro, or norite, or a variety of syenite called Larvikite if it is specifically from Larvik, Norway.
Mineral/Igneous Rock
Chert (Nodule)
Chert (mainly Microcrystalline or Cryptocrystalline Quartz, SiO2)
sedimentary
Quartzite River Rock
Quartzite (primarily SiO2)
metamorphic
Chert (Chert Nodule)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Quartz (chalcedony variety) or Limestone with Quartz Veins
SiO2 (for Quartz/Chalcedony); CaCO3 (for Limestone)
Mineral or Sedimentary Rock (with mineral inclusions)
Banded Gneiss
Gneiss (variable mineral composition)
metamorphic
Sandstone (Pebble/Cobble)
Sandstone (arenite is a more precise term for sandstone with less than 15% matrix; this specimen appears to be a lithic or quartz arenite)
Sedimentary
Diorite (Spotted or Dalmatian Stone pattern)
Diorite
igneous
Chert (Common Opal/Agate inclusion)
Microcrystalline Quartz (SiO2)
sedimentary
Granite
Granite
igneous
Anthracite Coal
Anthracite (Carbon-based metamorphic rock)
metamorphic
Serpentine
Serpentine-group ((Mg,Fe,Ni,Al,Zn,Mn)3(Si,Al,Fe)2O5(OH)4)
metamorphic
Chert (Gravel Bit)
Microcrystalline silica (SiO2)
sedimentary
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N/A
Ironstone Concretion (Ironstone Gourd)
Limonite/Goethite Concretion (FeOO(H))
sedimentary
Chert (specifically Flint)
Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)
sedimentary
Amethyst (Geode/Druzy)
Silicon Dioxide (SiO2) with iron impurities
mineral
Basalt (Stream-worn Cobble)
Mafic Igneous Rock (primarily Plagioclase and Pyroxene)
igneous
Sandstone (likely Greywacke variant)
Arenite
sedimentary
Basalt
Basalt (Mafic Extrusive Igneous Rock)
igneous
Feldspathic Granite (likely Syenite or Granite Pegmatite)
Phaneritic Acidic Igneous Rock (KAlSi3O8 dominant with SiO2)
igneous
Garnet-Bearing Gneiss
Almandine-Garnet Gneiss
metamorphic