Rock Identifier

Category

Organic (Often Found By Beachcombers)

Browse organic (often found by beachcombers) specimens identified by the Rock Identifier community.

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

Chert / Flint

Silicon Dioxide (SiO2)

Chert (with Limestone matrix) (Silicon dioxide (SiO2)) — sedimentary

Chert (with Limestone matrix)

Silicon dioxide (SiO2)

Red Jasper (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Red Jasper

Jasper (Silicon Dioxide, SiO2)

Chert (often called Flint or Jasper) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint or Jasper)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Sea Glass (Cobalt Blue) (Amorphous Silica (Glass with Cobalt additives)) — Anthropogenic specimen (man-made)

Sea Glass (Cobalt Blue)

Amorphous Silica (Glass with Cobalt additives)

Anthropogenic specimen (man-made)

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

Jasper

Silicon dioxide (SiO2) with impurities

Banded Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert

Microcrystalline Quartz (SiO2)

Chert (Jasper) (Microcrystalline Silica (SiO2)) — sedimentary

Chert (Jasper)

Microcrystalline Silica (SiO2)

Green Jasper (Silicon Dioxide (SiO2) with impurities of iron(II) silicate) — sedimentary

Green Jasper

Silicon Dioxide (SiO2) with impurities of iron(II) silicate

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

Chert (Flint)

Chert (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

Fossil Shark Tooth (Carcharodon or Carcharias fossil (Vertebrate Fossil)) — sedimentary

Fossil Shark Tooth

Carcharodon or Carcharias fossil (Vertebrate Fossil)

Jasper (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Jasper

Jasper (Silicon Dioxide, SiO2)

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

Chert / Flint

Silicon Dioxide (SiO2)

Chert (Yellow Jasper variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

Chalk (Calcium Carbonate (CaCO3)) — sedimentary

Chalk

Calcium Carbonate (CaCO3)

Petrified Wood (Silicified Wood (SiO2 - Silicon Dioxide)) — sedimentary

Petrified Wood

Silicified Wood (SiO2 - Silicon Dioxide)

Shale (Mudstone (composed primarily of clay minerals like kaolinite, illite, and smectite, with quartz and calcite)) — sedimentary

Shale

Mudstone (composed primarily of clay minerals like kaolinite, illite, and smectite, with quartz and calcite)

Chert (Iron-stained) (Chert / Microcrystalline Silicon Dioxide (SiO2)) — sedimentary

Chert (Iron-stained)

Chert / Microcrystalline Silicon Dioxide (SiO2)

Chert (often called Flint when in chalk or limestone) (Silicon Dioxide (SiO₂)) — sedimentary

Chert (often called Flint when in chalk or limestone)

Silicon Dioxide (SiO₂)

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

Chert (Nodule)

Silicon Dioxide (SiO2)

Chert (and Jasper/Flint variant) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (and Jasper/Flint variant)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (Nodule) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Nodule)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (Flint variety)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Red Chert (Jasper) (Silicon Dioxide (SiO2)) — sedimentary

Red Chert (Jasper)

Silicon Dioxide (SiO2)

Chert (Iron-stained) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Iron-stained)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

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

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Tahitian Pearl (Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3) — mineral

Tahitian Pearl

Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3

Banded Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Banded Chert

Microcrystalline Quartz (SiO2)

Geode (unopened) (Chert / Chalcedony Geode (SiO2)) — sedimentary

Geode (unopened)

Chert / Chalcedony Geode (SiO2)

Chert (Nodule) (Chert (primarily Microcrystalline Quartz - SiO2)) — sedimentary

Chert (Nodule)

Chert (primarily Microcrystalline Quartz - SiO2)

Chert (Lightly weathered variety) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (Lightly weathered variety)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (White Chert / Flint) (Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)) — sedimentary

Chert (White Chert / Flint)

Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)

Chert (Gravel pebble) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (Gravel pebble)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Red Jasper (Jasper (Silicon Dioxide, SiO2 with iron oxide impurities)) — sedimentary

Red Jasper

Jasper (Silicon Dioxide, SiO2 with iron oxide impurities)

Chert (Jasper/Flint variety) (Microcrystalline quartz (SiO2)) — sedimentary

Chert (Jasper/Flint variety)

Microcrystalline quartz (SiO2)

Chert (varietal: Flint or River Pebble) (Silicon Dioxide (SiO₂)) — sedimentary

Chert (varietal: Flint or River Pebble)

Silicon Dioxide (SiO₂)

Turquoise, Pearl, and Coral Necklace (CuAl6(PO4)4(OH)8·4H2O (Turquoise) / CaCO3 (Pearl and Coral)) — mineral

Turquoise, Pearl, and Coral Necklace

CuAl6(PO4)4(OH)8·4H2O (Turquoise) / CaCO3 (Pearl and Coral)

Petrified Wood (Silicified Wood (primarily SiO2 - Silicon Dioxide)) — sedimentary

Petrified Wood

Silicified Wood (primarily SiO2 - Silicon Dioxide)

Coal (likely Bituminous or Lignite) (Organic Sedimentary Rock (Carbonaceous)) — sedimentary

Coal (likely Bituminous or Lignite)

Organic Sedimentary Rock (Carbonaceous)

Ferruginous Sandstone (with possible trace fossils) (Arenite with Iron-Oxide Cement (SiO2 with Fe2O3)) — sedimentary

Ferruginous Sandstone (with possible trace fossils)

Arenite with Iron-Oxide Cement (SiO2 with Fe2O3)

Chert (often called Flint when dark) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (often called Flint when dark)

Microcrystalline or Cryptocrystalline Quartz (SiO2)