Scoria (vesicular volcanic rock)
Basaltic to andesitic scoria; chiefly plagioclase, pyroxene, and volcanic glass
igneous
Category
Metamorphic Or Igneous (Context Dependent)
Browse metamorphic or igneous (context dependent) specimens identified by the Rock Identifier community.
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Gemstone ring (stones not reliably identifiable from the image)
Likely faceted yellow stones and clear stones set in a metal band; species and treatments are indeterminate visually
gemstone
Native Gold (in the form of jewelry)
Gold (Au)
mineral
Granite Thin Section
Granitic rock (Phaneritic texture)
igneous
Chert / Flint Tool
Cryptocrystalline quartz (SiO2)
sedimentary
Chert / Flint (Artifact)
Microcrystalline Quartz (SiO2)
sedimentary
Chert / Flint Arrowhead
Microcrystalline Quartz (SiO2)
sedimentary
Nutting Stone / Cupstone (Sandstone or Quartzite)
Sedimentary rock with anthropogenic modification (cupule)
sedimentary
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
mineral
Morganite (Pink Beryl)
Beryllium aluminum silicate Be3Al2(SiO3)6
mineral
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
mineral
Porphyry
Porphyritic Andesite/Basalt
igneous
River Cobble (likely Serpentinite or Greenstone)
Serpentinite / Greenschist facies rock
metamorphic
Magnetite
Magnetite (Fe3O4)
Mineral
Sapphire Rough (Corundum)
Corundum (Aluminum Oxide, Al2O3)
mineral
Obsidian (likely Apache tear or flaked obsidian)
Volcanic glass; primarily rhyolitic silica glass (SiO₂-rich, non-crystalline)
igneous
Porphyry (Flower Stone)
Porphyry (Andesite or Basalt matrix)
igneous
Granite
Phaneritic plutonic rock (composed of Quartz, Feldspar, and Mica/Amphibole)
igneous
Quartz Pebble with Epidote / Chlorite Inclusions
Silicon Dioxide (SiO2) with Epidote/Chlorite inclusions
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milky calcite
Calcite (calcium carbonate, CaCO₃)
mineral
Painted Garden Rock (likely Granite or Limestone base)
Silicon Dioxide (SiO2) / Calcium Carbonate (CaCO3) based substrate with Acrylic/Enamel pigments
igneous or sedimentary (anthropogenic modification)
Sapphire
Corundum (Al2O3)
gemstone
Weathered sandstone fragment
Quartz-rich sandstone, possibly ferruginous sandstone
sedimentary
Possible obsidian (black volcanic glass)
Obsidian; natural silica-rich volcanic glass, composition typically rhyolitic
igneous
Pyrite-bearing quartz vein (likely pyrite ore)
Pyrite, FeS₂, with abundant quartz (SiO₂) and possibly chalcopyrite
mineral
Gold-Bearing Quartz Ore
Crystalline Silicon Dioxide (SiO2) with Trace Aurum (Au)
mineral
Quartz-rich hydrothermal vein rock, possibly quartzite
Mostly SiO₂ (quartz), with probable iron oxides and minor sulfides
metamorphic
Fine-grained gray rock, possibly basalt
Basalt (tentative; likely plagioclase–pyroxene rock)
igneous
Green Quartz (Prasiolite)
Silicon Dioxide (SiO2)
mineral
Ruby (set in a gold pendant)
Ruby (Variety of Corundum, Al2O3)
mineral
Mica Schist
Mica Schist (Quartz-Mica Schist)
metamorphic
Auriferous Quartz (Gold-bearing Quartz)
Silicon Dioxide (SiO2) with trace Gold (Au) and Iron Oxides
mineral
Kidney Stone
Calcium oxalate, uric acid, struvite, or cystine
mineral
Milky Quartz
Silicon Dioxide (SiO2)
mineral
Milk Quartz (White) and Yellow Aventurine (Yellow)
Silicon Dioxide (SiO2)
mineral
Citrine Quartz
Silicon Dioxide (SiO2)
mineral
Chert (Flint variety)
Microcrystalline context of Quartz (SiO2)
sedimentary
Yellow Sapphire
Corundum (Al2O3)
gemstone
Yellow Sapphire
Corundum (Al2O3)
gemstone
Milky Quartz with Iron Staining
Silicon Dioxide (SiO2)
mineral
Ruby / Red Tourmaline
Corundum (Al2O3) or Elbaite (Na(Li1.5Al1.5)Al6(Si6O18)(BO3)3(OH)4)
mineral