Quartzite Pebble
Quartzite (mostly SiO2)
metamorphic
Category
Rock
Browse rock specimens identified by the Rock Identifier community.
Painted River Pebble (likely Basalt or Greywacke)
Aphanitic Lithic Clast with Anthropogenic Pigment coating
Sedimentary or Igneous
Sandstone Cobble with Iron Staining
Arenite with Limonite/Hematite staining
sedimentary
Red Sandstone
Arenite (Iron-rich)
sedimentary
Quartz Vein in Metamorphic Rock
Quartzite or Schist host with Quartz (SiO2) intrusion
metamorphic
Red Jasper (Beach Pebble)
SiO2 (Microcrystalline Quartz with Hematite inclusions)
sedimentary
Sandstone
Clastic sedimentary rock (primarily SiO2)
sedimentary
Smooth river pebble, likely quartz-rich sandstone or quartzite
Probable quartz arenite (sandstone) or quartzite; mainly SiO₂ with minor iron-bearing minerals
sedimentary/metamorphic
Weathered granite or granitic gneiss boulder
Granite; predominantly quartz, feldspar, and mica (exact identification is uncertain from a photograph)
igneous
Granite-like rock
Felsic intrusive igneous rock, probably granitic or granodioritic
igneous
Small red-brown mineral or rock fragment
Unidentified; possibly iron-oxide-rich jasper, garnet, or weathered sulfide
mineral
Quartzite (Yellow/Orange variety)
Quartzite (primarily SiO2)
metamorphic
Jasper and Quartz Breccia
Silicified Breccia (Quartz / Chalcedony / Hematite)
sedimentary
Quartz-veined Metamorphic Pebble
Silicate-rich metamorphic rock with quartz veins (SiO2)
metamorphic
Granite River Rock
Intrusive igneous rock (composed mainly of quartz, alkali feldspar, and plagioclase)
igneous
Rounded brown river pebble
Indeterminate lithic clast; possibly weathered sandstone or fine-grained volcanic rock
sedimentary
Petrified Wood
Silicified wood (primarily quartz, SiO2)
fossil
Fossilized Bark
Lepidodendron / Sigillaria fossil impression
fossil
River Pebble (likely Quartzite or Siltstone)
Sedimentary Clast (SiO2 based)
sedimentary
Basalt with Alteration Crust
Basalt (SiO2 range 45-52%)
igneous
Leopard Skin Jasper
Orbicular Jasper (Silicon Dioxide, SiO2)
sedimentary
Basalt
Mafic Igneous Rock (composed primarily of plagioclase feldspar and pyroxene)
Igneous
Basalt
Mafic extrusive igneous rock
igneous
Clear Quartz (Cut/Faceted Gemstone)
Silicon Dioxide (SiO2)
gemstone
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Basalt
Basalt (Mafic volcanic rock)
igneous
Basalt Cobble
Aphanitic Mafic Igneous Rock (Basalt)
igneous
Basalt River Cobble
Basalt (Mafic volcanic rock)
igneous
Milky Quartz with Chlorite Schist Inclusions
Quartz (SiO2) with Chlorite Group silicates (typically (Mg,Fe)3(Si,Al)4O10(OH)2)
metamorphic
Granite
Phaneritic Igneous Rock (primarily Quartz, Feldspar, Mica)
igneous
Wishing Rock (Quartz Vein in Host Rock)
Silicon dioxide (SiO2) vein in various host rocks
Igneous/Sedimentary/Metamorphic with Mineral Vein
Quartz Geode (likely within Limestone or Dolomite matrix)
Quartz (SiO₂)
Mineral within a Sedimentary Rock
Granite-like cobble
Granitoid, likely biotite granite or granodiorite
igneous
Likely silver-gray granite or granitic gneiss fragment
Granite; primarily quartz (SiO₂), feldspar, and mica (exact identification uncertain from image)
igneous
River Rock
Mixed lithology clast
sedimentary
Quartz Druzy (Geode Fragment)
Silicon Dioxide (SiO2)
mineral
Coal (Bituminous / Anthracite)
Organic Sedimentary Rock (Carbonaceous Rock)
sedimentary
Coal
Coal (Sedimentary Rock / Organic Rock)
sedimentary
Pebble (likely Sandstone or Granitic Pebble)
Clastic Sediment (or specific rock type, e.g., Arenite, Granitoid Pebble)
Rock (likely Sedimentary)
Basalt with Weathering Rind
Basalt (Mafic Volcanic Rock)
igneous
Likely basalt or vesicular volcanic rock
Basalt, possibly scoriaceous basalt; exact identification is uncertain from the photograph
igneous
Greenstone pebble (likely altered basalt or serpentine)
Greenschist-facies mafic rock; commonly chlorite–actinolite–epidote ± serpentine
metamorphic