Rock Identifier

Category

Igneous Or Sedimentary (Water Worn)

Browse igneous or sedimentary (water worn) specimens identified by the Rock Identifier community.

Sandstone (Ferruginous) (Arenite (primarily SiO2 with Fe2O3 cement)) — sedimentary

Sandstone (Ferruginous)

Arenite (primarily SiO2 with Fe2O3 cement)

Conglomerate (Conglomerate (SiO2 primary clasts with lithic matrix)) — sedimentary

Conglomerate

Conglomerate (SiO2 primary clasts with lithic matrix)

Agate (Chert/Chalcedony) (Silicon Dioxide (SiO2)) — mineral

Agate (Chert/Chalcedony)

Silicon Dioxide (SiO2)

Yellow Jasper (Silicon Dioxide (SiO₂)) — sedimentary

Yellow Jasper

Silicon Dioxide (SiO₂)

Basalt (River Rock Cobble) (Extrusive mafic volcanic rock (Basalt)) — igneous

Basalt (River Rock Cobble)

Extrusive mafic volcanic rock (Basalt)

River Cobble (likely Basalt or Rhyolite) (Extrusive Igneous Rock (Mafic or Intermediate)) — igneous

River Cobble (likely Basalt or Rhyolite)

Extrusive Igneous Rock (Mafic or Intermediate)

Banded Agate (Agate (Cryptocrystalline Quartz, SiO2)) — mineral

Banded Agate

Agate (Cryptocrystalline Quartz, SiO2)

Chert (Pebble) (Microcrystalline silica (SiO2)) — sedimentary

Chert (Pebble)

Microcrystalline silica (SiO2)

Vesicular Basalt (Aqueous Tumbled) (Scoriaceous Basalt) — igneous

Vesicular Basalt (Aqueous Tumbled)

Scoriaceous Basalt

River Pebble (Siltstone/Mudstone) (Clastic sedimentary rock) — sedimentary

River Pebble (Siltstone/Mudstone)

Clastic sedimentary rock

Quartz (River Cobble) (Silicon Dioxide (SiO2)) — mineral

Quartz (River Cobble)

Silicon Dioxide (SiO2)

Garnet (Almandine (Fe3Al2(SiO4)3)) — mineral

Garnet

Almandine (Fe3Al2(SiO4)3)

Jasper (Silicon dioxide (SiO2) with impurities) — sedimentary

Jasper

Silicon dioxide (SiO2) with impurities

Crinoid Fossil in Chert (Siliceous limestone with Crinoidea fossil (SiO2)) — sedimentary

Crinoid Fossil in Chert

Siliceous limestone with Crinoidea fossil (SiO2)

Quartz Pebble (Sea Glass-like texture) (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble (Sea Glass-like texture)

Silicon Dioxide (SiO2)

Banded Chert (Silicon Dioxide (SiO2)) — sedimentary

Banded Chert

Silicon Dioxide (SiO2)

Basalt with Quartz/Calcite Vein (Amygdaloidal Basalt (matrix) with Mineral Vein filling) — igneous

Basalt with Quartz/Calcite Vein

Amygdaloidal Basalt (matrix) with Mineral Vein filling

Epidosite (Unakite-related) (Epidosite (predominantly Epidote, Ca2(Al2,Fe3+)(SiO4)3(OH))) — metamorphic

Epidosite (Unakite-related)

Epidosite (predominantly Epidote, Ca2(Al2,Fe3+)(SiO4)3(OH))

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Milky Quartz Pebble (Quartz (Silicon Dioxide, SiO2)) — mineral

Milky Quartz Pebble

Quartz (Silicon Dioxide, SiO2)

White Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

White Quartz Pebble

Silicon Dioxide (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Quartz (Milky Quartz) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky Quartz)

Silicon Dioxide (SiO2)

Basalt (Basalt) — igneous

Basalt

Basalt

Quartz (Iron-Stained) (Silicon Dioxide (SiO2)) — mineral

Quartz (Iron-Stained)

Silicon Dioxide (SiO2)

River Pebble (Gravel) (Clastic sedimentary rock (likely Siltstone or Mudstone pebble; SiO2 with various impurities)) — sedimentary

River Pebble (Gravel)

Clastic sedimentary rock (likely Siltstone or Mudstone pebble; SiO2 with various impurities)

Basalt River Stone (Basalt (Mafic volcanic rock)) — igneous

Basalt River Stone

Basalt (Mafic volcanic rock)

Yellow Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Yellow Quartz Pebble

Silicon Dioxide (SiO2)

Quartz Pebble (Silicon Dioxide (SiO2)) — Mineral / Sedimentary occurrence

Quartz Pebble

Silicon Dioxide (SiO2)

Mineral / Sedimentary occurrence

River Cobble (likely Basalt or Metagraywacke) (Non-specific water-worn lithic fragment) — igneous or metamorphic

River Cobble (likely Basalt or Metagraywacke)

Non-specific water-worn lithic fragment

igneous or metamorphic

Quartz (Quartz (Silicon Dioxide, SiO2)) — mineral

Quartz

Quartz (Silicon Dioxide, SiO2)

Basalt (Aphanitic Mafic Igneous Rock) — igneous

Basalt

Aphanitic Mafic Igneous Rock

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Granodiorite Pebble (Granodiorite) — igneous

Granodiorite Pebble

Granodiorite

Conglomerate (Conglomerate / Lithic Wacke) — sedimentary

Conglomerate

Conglomerate / Lithic Wacke

Jasper and Chert Conglomerate (Ferruginous Microcrystalline Quartz (SiO2)) — sedimentary

Jasper and Chert Conglomerate

Ferruginous Microcrystalline Quartz (SiO2)

Tumbled Green Jasper (Silicon Dioxide (SiO2) with mineral inclusions) — sedimentary

Tumbled Green Jasper

Silicon Dioxide (SiO2) with mineral inclusions

Chert (River Pebble) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (River Pebble)

Microcrystalline Quartz (SiO2)

Chert Pebble (Microcrystalline Quartz (SiO2)) — sedimentary

Chert Pebble

Microcrystalline Quartz (SiO2)

Chert (often called Flint or River Pebble) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint or River Pebble)

Microcrystalline Quartz (SiO2)

Chalcedony (Carnelian/Agate variety) (Silicon Dioxide (SiO2) with trace hematite/iron impurities) — mineral

Chalcedony (Carnelian/Agate variety)

Silicon Dioxide (SiO2) with trace hematite/iron impurities

Chalcedony (Agate/Carnelian type) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Agate/Carnelian type)

Silicon Dioxide (SiO2)