Igneous Rock

Browse igneous rock specimens identified by the Rock Identifier community.

Granite Gneiss

Gneiss (High-grade regional metamorphic rock)

Metamorphic

Gneiss

Gneiss (High-grade regional metamorphic rock)

Metamorphic

Gold Ore in Quartz/Schist

Auriferous Quartz and Sulfide-bearing Schist

Metamorphic/Igneous (Hydrothermal)

Gneiss

Gneiss (High-grade metamorphic rock composed primarily of Quartz, Feldspar, and various Micas)

metamorphic

Schist

Mica Schist (primarily Muscovite or Biotite sheet silicates)

metamorphic

Citrine

Citrine (Silicon Dioxide - SiO2)

mineral

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

metamorphic

Gneiss

Gneiss (High-grade regional metamorphic rock)

metamorphic

Quartz with Iron Stains

Quartz (SiO2) with iron oxide/hydroxide staining

Mineral

Amethyst

Amethyst (Silicon Dioxide, SiO2)

mineral

Yellow Quartz (Citrine-colored Quartz Pebble)

Silicon Dioxide (SiO2)

mineral

Banded Gneiss

Gneiss (High-grade regional metamorphic rock)

metamorphic

Quartz (Rock Crystal) with minor impurities

Quartz (SiO2)

Mineral

Thunderegg (Agate-filled Geode Node)

Silicon dioxide (SiO2) with various inclusions

sedimentary/igneous association

Quartz

Silicon Dioxide (SiO2)

Mineral

Rock Crystal Quartz

Quartz (SiO₂)

Mineral

Moss Agate

Chalcedony (SiO2) with dendritic inclusions of Manganese or Iron oxide

mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

mineral

Quartz (Clear Quartz/Rock Crystal)

Silicon Dioxide (SiO2)

mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

mineral

Clear Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

mineral

Banded Gneiss

Gneiss (High-grade Regional Metamorphic Rock)

metamorphic

Veined Quartz

SiO2 (Silicon Dioxide)

Mineral

Gneiss

Gneiss (a type of metamorphic rock)

Metamorphic Rock

Quartz Geode Fragment

Silicon Dioxide (SiO2)

mineral

River Cobble (likely Basalt or Chert)

Siliceous River Rock / Microcrystalline Quartz / Mafic Igneous

igneous/sedimentary

Gold Ore in Matrix

Native Gold (Au) in Quartz/Limonite host rock

mineral

Garnet (Almandine or Spessartine likely)

Garnet Group Minerals (e.g., Almandine Fe3Al2(SiO4)3, Pyrope Mg3Al2(SiO4)3, Spessartine Mn3Al2(SiO4)3)

Mineral

Quartz

Quartz (SiO2 - Silicon Dioxide)

Mineral

Almandine Garnet

Iron aluminum silicate (Fe3Al2(SiO4)3)

Mineral

Pebble (likely Quartz or Chert)

SiO₂ (Silicon Dioxide) - referring to the likely main mineral composition, Quartz. If it's chert, the scientific name remains SiO₂ with a microcrystalline structure.

Sedimentary Rock

Bull Quartz (Milky Quartz)

Quartz (Silicon Dioxide - SiO2)

mineral

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

mineral

Vesicular Basalt (Amygdaloidal)

Vesicular Basalt (Fe-Mg rich extrusive volcanic rock)

igneous

Yellow Apatite Sphere (Polished)

Fluorapatite / Ca5(PO4)3F

mineral

Milky Quartz with Iron Staining

Silicon Dioxide (SiO2)

mineral

Quartz

Silicon Dioxide (SiO₂)

Mineral

Granite Glacial Erratic

Phaneritic Plutonic Felsic Rock (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8 – SiO2)

igneous

Granite

Phaneritic Plutonic Felsic Rock (SiO2, KAlSi3O8, NaAlSi3O8, CaAl2Si2O8)

igneous

Granite

Phaneritic plutonic rock (dominated by SiO2, Al2O3, K2O, Na2O)

igneous

Granitic Gravel Piece

Granite (Felsic Plutonic Rock / SiO2 with Al2O3, K2O, Na2O)

igneous