Mica (Biotite or Phlogopite variety)
Phyllosilicate (complex mineral formula involving K, Mg, Fe, Al, Si, and O)
mineral
Category
Metamorphic Or Igneous (Context Dependent)
Browse metamorphic or igneous (context dependent) specimens identified by the Rock Identifier community.
Learn about Metamorphic Or Igneous (Context Dependent) in the encyclopedia
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Chert (Nodule)
Silicon Dioxide (SiO2)
sedimentary
Yellow Jasper
Silicon Dioxide (SiO2)
sedimentary
Chert (varietal Chalcedony or Flint)
Silicon dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Massive Quartz with Host Rock
Silicon Dioxide (SiO2)
mineral
Tumbled purple agate (likely grape agate or amethystine chalcedony)
Microcrystalline quartz, SiO₂; purple coloration commonly from iron, manganese, or inclusions
mineral
Fossilized cylindrical shell or bone fragment
Indeterminate biogenic carbonate or phosphatic fossil; possible fragment of a tubular shell (e.g., scaphopod) or hollow bone
fossil
Glass / Silicon Dioxide (Man-made)
SiO2 (Amorphous Silicon Dioxide)
Amorphous Solid
Sea Shell (Fighting Conch Fragment)
Calcium Carbonate (CaCO3) - Strombus alatus fragment
sedimentary (biogenic)
Chert (Flint Nodules)
Silicon Dioxide (SiO2)
sedimentary
Chert (with nodule)
Microcrystalline Quartz (SiO2)
sedimentary
Gold Nugget
Native Gold (Au)
mineral
Jade (Nephrite or Jadeite)
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (Na(Al,Fe3+)Si2O6)
Metamorphic Rock / Mineral
Iron Slag (Industrial Byproduct)
Anthropogenic Vitrification Product/Ferrous Slag
Mineral-like Industrial Smelting Waste
Ironstone Concretion (Moqui Marble)
Iron-oxide concretion (Fe2O3 / FeO(OH))
sedimentary
Ferruginous Sandstone (Ironstone Conglomerate fragments)
Ferruginous clastic sedimentary rock (SiO2 cemented by Fe2O3)
sedimentary
Sandstone Concretion
Limonitic Sandstone Concretion
sedimentary
Limonite-pseudomorph after Pyrite (Prophecy Stone)
Goethite and Limonite secondary minerals (FeO(OH)·nH2O) replacing Pyrite (FeS2)
mineral
Yellow Jasper
Chalcedony (SiO2) with iron oxide inclusions
mineral
Pyrite on Quartz (Fool's Gold in Quartz)
Iron Sulfide (FeS2) on Silicon Dioxide (SiO2)
mineral
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
mineral
Sandstone (Nut-stone / Cup-stone artifact)
Quartz Arenite / Worked Sedimentary Rock
sedimentary
Chert (specifically Flint or Dark Chert)
Silicon Dioxide (SiO2)
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Graywacke
Graywacke
sedimentary
Red Sandstone
Arenite (primarily composed of SiO2 with Fe2O3 cement)
sedimentary
Pyrite in Quartz
Iron Sulfide (FeS2) in Silicon Dioxide (SiO2)
mineral
Gossan (Iron Hat) with Quartz and Chlorite
Limonite/Goethite-rich Gossan (FeO(OH)·nH2O) with inclusions of Quartz and Chlorite
Mineral/Metamorphic Substrate
Shale with Pyrite
Clastic sedimentary rock containing Iron Disulfide (FeS2)
sedimentary
Chalcedony Geode / Agate Nodule
Cryptocrystalline Quartz (SiO2)
mineral
Red Jasper
Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)
sedimentary
Cobaltian Calcite (Cobaltoan Calcite)
Cobalt-bearing Calcite (Ca,Co)CO3
mineral
Ferruginous Sandstone
Arenite with Iron-Oxide Cement (FeO(OH)·nH2O / Fe2O3)
sedimentary
Hag Stone
Perforated Sandstone (composed of SiO2 and calcareous cement)
sedimentary
Green Moonstone (Garnierite)
Nickel-bearing Magnesium Silicate (often a mix of Serpentine and Talc/Chlorite groups)
mineral
Quartz Vein in Host Rock
Silicon Dioxide (SiO2) within Metasedimentary or Igneous Matrix
metamorphic
Chert (Arrowhead/Projectile Point)
Chert (Cryptocrystalline Quartz, SiO2)
sedimentary
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
mineral