Banded Gneiss (River Rock/Pebble)
Gneiss (specifically a banded variety, likely a orthogneiss or paragneiss depending on parent rock)
Metamorphic Rock
Category
Sedimentary Rock
Browse sedimentary rock specimens identified by the Rock Identifier community.
Basalt Cobble
Vesicular Basalt (Mafic Extrusive)
igneous
Granodiorite
Granodiorite
igneous
Pink Dyed Agate (Pink Agate Slice)
Silicon Dioxide (SiO2) - Chalcedony / Cryptocrystalline Quartz
mineral
Agate Slices and Clear Quartz Points
Agate (SiO2 Chalcedony) and Clear Quartz (SiO2 Crystalline)
mineral
Quartz
Silicon Dioxide (SiO₂)
Mineral
Chert (specifically Iron-stained River Cobble)
Silicon Dioxide (SiO2)
sedimentary
Quartz
Quartz (SiO₂)
Mineral
Chert (Hagstone/Gasket Rock variant)
Chert (SiO2)
sedimentary
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Quartz
Silicon Dioxide (SiO₂)
Mineral
Quartz (likely milky/rose quartz variety)
Quartz (SiO2 - Silicon Dioxide)
Mineral
Gneiss
Gneiss (High-grade regional metamorphic rock)
metamorphic
Vesicular Basalt (Pumice-like)
Vesicular Basalt
igneous
Granodiorite
Granodiorite (containing Plagioclase, Quartz, and Biotite)
igneous
Serpentine
Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4
metamorphic
Pink Granite
Phaneritic Felsic Intrusive Igneous Rock
igneous
Desert Rose (Baryte or Selenite variant)
Barium Sulfate (BaSO4) or Gypsum (CaSO4·2H2O) with Sand inclusions
mineral
Quartz / Chert
Silicon Dioxide (SiO2)
Mineral / Sedimentary
Marble
Marble (metamorphosed limestone/dolostone). Predominantly composed of Calcite (CaCO3) for marble derived from limestone, or Dolomite (CaMg(CO3)2) for marble derived from dolostone.
Metamorphic Rock
River Pebble (likely Quartzite or Chert)
Silicon Dioxide (SiO2) crystal conglomerate
sedimentary or metamorphic
Lapis Lazuli
Lapis Lazuli (a rock composed primarily of Lazurite)
Metamorphic rock
Dalmatian Jasper (Dalmatian Stone)
Dalmatian Stone (primarily Feldspar, Quartz, and Arfvedsonite/Tourmaline)
igneous
Granodiorite (Gneissic texture)
Granodiorite (containing Quartz SiO2, Plagioclase Feldspar, and Biotite)
igneous
Basalt (Vesicular)
Basalt (Extrusive Volcanic Rock)
igneous
Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
River/Stream Pebble
Clast / Detrital Grain / Rounded Sedimentary Particle (Compositionally variable, commonly Quartz, Feldspar, Chert, or other resistant rock fragments)
Mineral, specifically a rock fragment
Yellow Quartzite (River Pebble)
Quartzite (SiO2)
metamorphic
Exposed Aggregate Concrete (Pea Gravel)
Concrete with Siliceous Alluvial Gravels
sedimentary (man-made conglomerate)
Chert (Flint)
Chert (predominantly SiO₂ - silicon dioxide)
sedimentary
Biotite Mica
Biotite, K(Mg,Fe)3AlSi3O10(F,OH)2
mineral
Gneiss (specifically a Banded Gneiss pebble)
Gneiss (High-grade Regional Metamorphic Rock)
metamorphic
Quartz (vein quartz)
SiO2 (Silicon Dioxide)
Mineral
Porphyry (Flower Stone)
Porphyry (Andesite or Basalt matrix)
igneous
Basalt with inclusion
Basalt (Aphanitic-Porphyritic texture)
igneous
Basalt with Scoria
Amygdaloidal Basalt / Vesicular Basalt
igneous
Druzy Quartz on Chert/Chalcedony
Silicon Dioxide (SiO2)
mineral
Quartz
Quartz (SiO₂)
Mineral
Schist
N/A (a rock type, not a mineral formula)
metamorphic
Basalt
Basalt (Mafic volcanic rock)
igneous
Asphalt (Road Aggregate)
Asphalt concrete / Bituminous mixture
anthropogenic sedimentary (technolith)
Chert (Yellow Jasper/Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary