Rock Identifier

Category

Igneous Or Sedimentary (Water Worn)

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

River Rock (likely Basalt or Greywacke) (Basalt or Lithic Sandstone) — Igneous or Sedimentary (water-worn)

River Rock (likely Basalt or Greywacke)

Basalt or Lithic Sandstone

Igneous or Sedimentary (water-worn)

Greenstone / Glauconitic Siltstone (Metabasalt or Glauconite-rich Sedimentary Rock) — metamorphic or sedimentary

Greenstone / Glauconitic Siltstone

Metabasalt or Glauconite-rich Sedimentary Rock

metamorphic or sedimentary

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

Quartz (Small Pebble)

Silicon Dioxide (SiO2)

Quartz (Pale Rose or Milky Variety) (Silicon Dioxide (SiO2)) — mineral

Quartz (Pale Rose or Milky Variety)

Silicon Dioxide (SiO2)

Yellow Quartz (Citrine/Yellow Jasper) (Silicon Dioxide (SiO2)) — mineral

Yellow Quartz (Citrine/Yellow Jasper)

Silicon Dioxide (SiO2)

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Quartz (Milky or Yellow variety) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky or Yellow variety)

Silicon Dioxide (SiO2)

Milky Quartz Pebble with Chert (Silicon Dioxide (SiO2)) — mineral

Milky Quartz Pebble with Chert

Silicon Dioxide (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

General Gravel (River Rock/River Stones) (Mixed Lithic Sediments (Conglomerate Clasts)) — sedimentary

General Gravel (River Rock/River Stones)

Mixed Lithic Sediments (Conglomerate Clasts)

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

River Rock (Basalt/Greywacke) (Aphanitic Basalt or Lithic Sandstone (Greywacke)) — igneous

River Rock (Basalt/Greywacke)

Aphanitic Basalt or Lithic Sandstone (Greywacke)

Quartz (Agate/Chalcedony variety) (Silicon Dioxide (SiO2)) — mineral

Quartz (Agate/Chalcedony variety)

Silicon Dioxide (SiO2)

Chalcedony (Smoky Quartz or Agate nodule fragment) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Smoky Quartz or Agate nodule fragment)

Silicon Dioxide (SiO2)

Jasper Agate (Chalcedony) (Silicon Dioxide (SiO2)) — sedimentary

Jasper Agate (Chalcedony)

Silicon Dioxide (SiO2)

Quartz (Smoky or Clear variety with inclusions) (Silicon Dioxide (SiO2)) — mineral

Quartz (Smoky or Clear variety with inclusions)

Silicon Dioxide (SiO2)

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

Chalcedony (Agate)

Silicon Dioxide (SiO2)

Carnelian (Carnelian Agate) (Carnelian (Silicon Dioxide - SiO2)) — mineral

Carnelian (Carnelian Agate)

Carnelian (Silicon Dioxide - SiO2)

Pebble (likely Sandstone or Granitic Pebble) (Clastic Sediment (or specific rock type, e.g., Arenite, Granitoid Pebble)) — Rock (likely Sedimentary)

Pebble (likely Sandstone or Granitic Pebble)

Clastic Sediment (or specific rock type, e.g., Arenite, Granitoid Pebble)

Rock (likely Sedimentary)

Quartz (Milky or Clear variety) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky or Clear variety)

Silicon Dioxide (SiO2)

Chalcedony (Agate/Blue Quartzite) (Silicon Dioxide (SiO2)) — mineral

Chalcedony (Agate/Blue Quartzite)

Silicon Dioxide (SiO2)

Gneiss (Metamorphic Rock) (Gneiss) — metamorphic

Gneiss (Metamorphic Rock)

Gneiss

Cryptocrystalline Quartz (Agate/Chert) (Silicon dioxide (SiO2)) — sedimentary

Cryptocrystalline Quartz (Agate/Chert)

Silicon dioxide (SiO2)

Rough Agate/Chert Nodules (Cryptocrystalline Quartz (SiO2)) — sedimentary

Rough Agate/Chert Nodules

Cryptocrystalline Quartz (SiO2)

Yellow Chalcedony (likely carnelian or yellow agate) (Silicon Dioxide (SiO₂)) — mineral

Yellow Chalcedony (likely carnelian or yellow agate)

Silicon Dioxide (SiO₂)

River Stone (Chalcedony/Jasper variety) (Microcrystalline Quartz (SiO2)) — sedimentary

River Stone (Chalcedony/Jasper variety)

Microcrystalline Quartz (SiO2)

River Cobble (Gneiss/Schist mix) (Foliated Metamorphic Rock (Gneissic/Schistose)) — metamorphic

River Cobble (Gneiss/Schist mix)

Foliated Metamorphic Rock (Gneissic/Schistose)

Chalcedony with inclusions (Agate/Quartz) (Silicon Dioxide (SiO2)) — mineral

Chalcedony with inclusions (Agate/Quartz)

Silicon Dioxide (SiO2)

Quartz (Milky/Iron-stained) (Silicon Dioxide (SiO2)) — mineral

Quartz (Milky/Iron-stained)

Silicon Dioxide (SiO2)

Greenstone / Chert (Cryptocrystalline Quartz (SiO2) or Altered Basalt) — sedimentary or metamorphic

Greenstone / Chert

Cryptocrystalline Quartz (SiO2) or Altered Basalt

sedimentary or metamorphic

Quartz / Common Agate (Silicon Dioxide (SiO2)) — mineral

Quartz / Common Agate

Silicon Dioxide (SiO2)

River Rocks (Basalt and Sedimentary Stones) (Mafic Igneous Rock (Basalt) and Clastic Sedimentary Rock) — igneous and sedimentary

River Rocks (Basalt and Sedimentary Stones)

Mafic Igneous Rock (Basalt) and Clastic Sedimentary Rock

igneous and sedimentary

Black Sand (Magnetite Sand) (Magnetite-rich Placers (Fe3O4)) — sedimentary

Black Sand (Magnetite Sand)

Magnetite-rich Placers (Fe3O4)

Chalcedony (Moonstone-like Agate) (Silicon Dioxide (SiO₂)) — mineral

Chalcedony (Moonstone-like Agate)

Silicon Dioxide (SiO₂)

Leopard Skin Jasper (Silicon Dioxide (SiO2) with various inclusions) — sedimentary

Leopard Skin Jasper

Silicon Dioxide (SiO2) with various inclusions

Yellow Quartz (Citrine or Yellow Chalcedony) (Silicon Dioxide (SiO2)) — mineral

Yellow Quartz (Citrine or Yellow Chalcedony)

Silicon Dioxide (SiO2)

Gneiss (Metamorphic Rock) (Gneiss (high-grade regional metamorphic rock)) — metamorphic

Gneiss (Metamorphic Rock)

Gneiss (high-grade regional metamorphic rock)

Sandstone (Quartz-rich) (Arenite (composed primarily of SiO2)) — sedimentary

Sandstone (Quartz-rich)

Arenite (composed primarily of SiO2)

Hag Stone (Sandstone with Boreholes) (Bored Sandstone (Sedimentary rock with lithophaga-style borings)) — sedimentary

Hag Stone (Sandstone with Boreholes)

Bored Sandstone (Sedimentary rock with lithophaga-style borings)

Chert (Beach Pebble) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Beach Pebble)

Silicon Dioxide (SiO2)

River Cobble (likely Basalt or Chert) (Siliceous River Rock / Microcrystalline Quartz / Mafic Igneous) — igneous/sedimentary

River Cobble (likely Basalt or Chert)

Siliceous River Rock / Microcrystalline Quartz / Mafic Igneous

igneous/sedimentary

Yellow Chalcedony (Agate Pebble) (Silicon Dioxide (SiO2) - Cryptocrystalline Quartz) — mineral

Yellow Chalcedony (Agate Pebble)

Silicon Dioxide (SiO2) - Cryptocrystalline Quartz