Porphyritic Rhyolite (Red Porp)
Porphyritic Rhyolite (Felsic volcanic rock)
igneous
Category
Man Made
Browse man made specimens identified by the Rock Identifier community.
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Sandstone
Arenite
sedimentary
Limonite Concretion
FeO(OH)·nH2O (Hydrated Iron Oxide)
sedimentary
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)
metamorphic
Granite
Phaneritic Igneous Rock (primarily Quartz, Feldspar, and Mica)
igneous
Jasper
Jasper (Silica-rich microcrystalline Quartz, SiO2 with Fe2O3 impurities)
sedimentary
Red Sandstone
Arenite (SiO2 with Fe2O3)
sedimentary
Quartz (Citrine or Iron-Stained)
Silicon Dioxide (SiO2)
mineral
Sandstone
Arenite (Quartz-rich sedimentary rock)
sedimentary
Sandstone (Stream-rounded)
Arenite (SiO2 based)
sedimentary
Iron Ore / Ironstone Concretion
Mixture of iron oxide/hydroxide minerals, likely some combination of Hematite (Fe2O3), Goethite (α-FeOOH), and Limonite (a general term for hydrated iron oxides of variable composition) or potentially Bauxite (a mixture of aluminum hydroxides, often with iron oxides, (Al(OH)3) and FeO(OH)). The visual characteristics strongly suggest iron-rich material.
Mineral, specifically an iron ore
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Quartzite
Quartzite (SiO2)
metamorphic
Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
mineral
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Fluorite on Matrix
Calcium Fluoride (CaF2)
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Limonite (Iron Ore)
Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O)
Mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Turquoise color-bead and Hematite necklace
Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Hematite (Fe2O3)
mineral
Petrified Wood
Silicified wood, primarily composed of Quartz (SiO2)
Mineral, often found in sedimentary deposits
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
sedimentary
Sandstone
Sandstone (SiO2 dominated)
sedimentary
Fluorite
Calcium Fluoride (CaF2)
mineral
Greenstone / Diorite
Intermediate plutonic igneous rock
igneous
Green Fluorite
Fluorite (Calcium Fluoride) - CaF2
mineral
Sandstone
Arenite (primarily Quartz, SiO2)
sedimentary
Amber
Succinite (Fossilized Tree Resin)
mineral
Pegmatite (Granite Pegmatite)
Intrusive Igneous Rock (Granite Pegmatite)
igneous
Limonite (often after Pyrite)
Limonite (FeO(OH)·nH2O)
mineral
Native Copper
Native Copper (Cu)
mineral
River Cobble (Sandstone)
Arenite / Quartz Sandstone
sedimentary
Chert (and its variety Flint)
Silicon Dioxide (SiO2) - Microcrystalline or cryptocrystalline Quartz
sedimentary
Gneiss
Gneiss
metamorphic
Chert (variations include Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Prehnite
Prehnite (Ca2Al2Si3O10(OH)2)
mineral
Serpentine
Serpentinite (a rock composed primarily of serpentine minerals like antigorite, chrysotile, and lizardite; general formula (Mg, Fe)3Si2O5(OH)4)
metamorphic