Rock Identifier

Category

Artifact

Browse artifact specimens identified by the Rock Identifier community.

Obsidian (black volcanic glass) (Obsidian; predominantly silica-rich volcanic glass, commonly rhyolitic (approximately 70–75% SiO₂)) — igneous

Obsidian (black volcanic glass)

Obsidian; predominantly silica-rich volcanic glass, commonly rhyolitic (approximately 70–75% SiO₂)

Sandstone concretion (Arenite sedimentary rock (concretion/nodule)) — sedimentary

Sandstone concretion

Arenite sedimentary rock (concretion/nodule)

Chert (Microcrystalline quartz (SiO2)) — sedimentary

Chert

Microcrystalline quartz (SiO2)

Concretion (Sedimentary Concretion (Ironstone / Calcite Concretion)) — sedimentary

Concretion

Sedimentary Concretion (Ironstone / Calcite Concretion)

Sandstone Concretion (Sedimentary Clastic Rock (Silicate-rich)) — sedimentary

Sandstone Concretion

Sedimentary Clastic Rock (Silicate-rich)

Diorite (Intrusive Igneous Rock (Intermediate Composition)) — igneous

Diorite

Intrusive Igneous Rock (Intermediate Composition)

Sandstone Concretion (Clastic Sedimentary Concretion (typically Quartz/Silica with Iron Oxide)) — sedimentary

Sandstone Concretion

Clastic Sedimentary Concretion (typically Quartz/Silica with Iron Oxide)

Lapis Lazuli (Lapis Lazuli (Complex silicate mixture)) — metamorphic

Lapis Lazuli

Lapis Lazuli (Complex silicate mixture)

Red Jasper (Opaque Chalcedony) (Silicon Dioxide (SiO2) with Hematite impurities) — mineral

Red Jasper (Opaque Chalcedony)

Silicon Dioxide (SiO2) with Hematite impurities

Libyan Desert Glass (Libyan Desert Glass (SiO2 with trace elements)) — mineral (impactite)

Libyan Desert Glass

Libyan Desert Glass (SiO2 with trace elements)

mineral (impactite)

Yellow Jasper (Silicon Dioxide (SiO2)) — sedimentary

Yellow Jasper

Silicon Dioxide (SiO2)

Connemara Marble (Ophiocalcite (Serpentinitic Marble)) — metamorphic

Connemara Marble

Ophiocalcite (Serpentinitic Marble)

Turquoise and Red Coral (with Grizzly Bear Claw) (Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Precious Coral (Corallium rubrum)) — mineral

Turquoise and Red Coral (with Grizzly Bear Claw)

Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Precious Coral (Corallium rubrum)

Jadeite (variety of Jade) (Jadeite, NaAlSi₂O₆) — metamorphic

Jadeite (variety of Jade)

Jadeite, NaAlSi₂O₆

Chert (Silicon dioxide (SiO2) - Microcrystalline quartz) — sedimentary

Chert

Silicon dioxide (SiO2) - Microcrystalline quartz

Dzi Bead (Agate) (Chalcedony (cryptocrystalline variety of Quartz), SiO2) — mineral

Dzi Bead (Agate)

Chalcedony (cryptocrystalline variety of Quartz), SiO2

River Pebble (Quartzite pebble) — sedimentary

River Pebble

Quartzite pebble

Chert (Chalcedony/Agate) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Chalcedony/Agate)

Microcrystalline Quartz (SiO2)

Diorite (Diorite) — igneous

Diorite

Diorite

Sandstone Concretion (Septarian or Carbonate-cemented Sandstone Concretion) — sedimentary

Sandstone Concretion

Septarian or Carbonate-cemented Sandstone Concretion

Polished black gemstone, likely obsidian (Volcanic glass; chiefly silica-rich amorphous SiO₂) — igneous

Polished black gemstone, likely obsidian

Volcanic glass; chiefly silica-rich amorphous SiO₂

Carnelian (Red Chalcedony) (Silicon Dioxide (SiO2) with iron oxide impurities) — mineral

Carnelian (Red Chalcedony)

Silicon Dioxide (SiO2) with iron oxide impurities

Obsidian arrowhead flakes (Volcanic glass; primarily silica-rich rhyolitic composition (approximately 70–75% SiO₂)) — igneous

Obsidian arrowhead flakes

Volcanic glass; primarily silica-rich rhyolitic composition (approximately 70–75% SiO₂)

Chert (Flint) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Flint)

Microcrystalline Quartz (SiO2)

Flint (Chert Nodule) (Microcrystalline Quartz (SiO2)) — sedimentary

Flint (Chert Nodule)

Microcrystalline Quartz (SiO2)

Chert (Flint) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (Chalcedony/Flint) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Chalcedony/Flint)

Silicon Dioxide (SiO2)

Flint nodule (Sedimentary cryptocrystalline quartz (SiO2)) — sedimentary

Flint nodule

Sedimentary cryptocrystalline quartz (SiO2)

Chert (Flint) (Silicon dioxide (microcrystalline quartz, SiO2)) — sedimentary

Chert (Flint)

Silicon dioxide (microcrystalline quartz, SiO2)

Jasper Arrowhead (Flint/Chert) (Microcrystalline Quartz (SiO2)) — sedimentary

Jasper Arrowhead (Flint/Chert)

Microcrystalline Quartz (SiO2)

Chert (Flint) (Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)) — sedimentary

Chert (Flint)

Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)

Chert (specifically Tan Chert) (Chert (SiO2)) — sedimentary

Chert (specifically Tan Chert)

Chert (SiO2)

Chert (Flint) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Flint)

Microcrystalline Quartz (SiO2)

Chert (variations include Flint/Chalcedony) (Chert (SiO2 - Silicon Dioxide)) — sedimentary

Chert (variations include Flint/Chalcedony)

Chert (SiO2 - Silicon Dioxide)

Chert (Flint) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Flint)

Silicon Dioxide (SiO2)

Diorite (Diorite (Intermediate intrusive igneous rock)) — igneous

Diorite

Diorite (Intermediate intrusive igneous rock)

Chert (variations include Flint or Jasper) (Chert (SiO2)) — sedimentary

Chert (variations include Flint or Jasper)

Chert (SiO2)

Chert (Grey-Green Var.) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Grey-Green Var.)

Silicon Dioxide (SiO2)

Chert (and associated Sedimentary rocks) (Microcrystalline Silica (SiO2)) — sedimentary

Chert (and associated Sedimentary rocks)

Microcrystalline Silica (SiO2)

Greenstone (Metabasalt / Greenstone) — metamorphic

Greenstone

Metabasalt / Greenstone

Chert (Flint/Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Flint/Jasper)

Silicon Dioxide (SiO2)

Diorite (Diorite (Intermediate intrusive igneous rock)) — igneous

Diorite

Diorite (Intermediate intrusive igneous rock)