Rock Identifier

Category

Organic (Often Found By Beachcombers)

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

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

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

Chalcedony (Agate/Chert)

Silicon Dioxide (SiO₂)

mineral
Granite (Plutonic felsic igneous rock) — igneous

Granite

Plutonic felsic igneous rock

igneous
Granite Gneiss (Gneiss (High-grade metamorphic rock)) — metamorphic

Granite Gneiss

Gneiss (High-grade metamorphic rock)

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

Milky Quartz Pebble

Silicon Dioxide (SiO2)

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

Chert (specifically Tan Chert)

Chert (SiO2)

sedimentary
Green Aventurine (Silicon Dioxide with Fuchsite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)) — mineral

Green Aventurine

Silicon Dioxide with Fuchsite inclusions (SiO2 + K(Al,Cr)2AlSi3O10(OH)2)

mineral
Black Onyx (Cryptocrystalline Chalcedony (SiO2)) — mineral

Black Onyx

Cryptocrystalline Chalcedony (SiO2)

mineral
Rose Quartz (Silicon Dioxide (SiO2) with trace elements of titanium, iron, or manganese) — mineral

Rose Quartz

Silicon Dioxide (SiO2) with trace elements of titanium, iron, or manganese

mineral
Chert (Basanite variety) with Quartz Vein (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Basanite variety) with Quartz Vein

Microcrystalline Quartz (SiO2)

sedimentary
Serpentinite (Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4) — metamorphic

Serpentinite

Serpentinite (Mg, Fe, Ni, Al, Zn, Mn)2-3(Si, Al, Fe)2O5(OH)4

metamorphic
Mica Schist (Mica Schist) — metamorphic

Mica Schist

Mica Schist

metamorphic
Fossilized Brachiopod/Bivalve in Limestone (Brachiopoda or Bivalvia fossil in Calcite/Limestone (CaCO3)) — sedimentary

Fossilized Brachiopod/Bivalve in Limestone

Brachiopoda or Bivalvia fossil in Calcite/Limestone (CaCO3)

sedimentary
Wild Horse Magnesite (Magnesite with Hematite inclusions (MgCO3)) — mineral

Wild Horse Magnesite

Magnesite with Hematite inclusions (MgCO3)

mineral
Banded Sandstone (Arenite with Liesegang banding (primarily SiO2 with FeO(OH) impurities)) — sedimentary

Banded Sandstone

Arenite with Liesegang banding (primarily SiO2 with FeO(OH) impurities)

sedimentary
Basalt (Basalt (Mafic volcanic rock)) — igneous

Basalt

Basalt (Mafic volcanic rock)

igneous
Sandstone (Clastic Sedimentary Rock (composed mostly of quartz, SiO2)) — sedimentary

Sandstone

Clastic Sedimentary Rock (composed mostly of quartz, SiO2)

sedimentary
Quartz (Druzy) (Silicon Dioxide (SiO2)) — mineral

Quartz (Druzy)

Silicon Dioxide (SiO2)

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

Quartz (Milky or Cloudy Quartz)

Silicon Dioxide (SiO2)

mineral
Chert (Common Opal/Jasper variety) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Common Opal/Jasper variety)

Silicon Dioxide (SiO2)

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

Quartz Pebble

Silicon Dioxide (SiO2)

mineral
Sandstone (with manganese staining) (Clastic sedimentary rock (primarily SiO2)) — sedimentary

Sandstone (with manganese staining)

Clastic sedimentary rock (primarily SiO2)

sedimentary
Mica Schist with Garnet (Garnetiferous Mica Schist) — metamorphic

Mica Schist with Garnet

Garnetiferous Mica Schist

metamorphic
Milky Quartz Vein with Matrix (Silicon Dioxide (SiO2)) — mineral

Milky Quartz Vein with Matrix

Silicon Dioxide (SiO2)

mineral
Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

metamorphic
Chert (Microcrystalline Quartz (SiO2)) — sedimentary

Chert

Microcrystalline Quartz (SiO2)

sedimentary
Fluorite (Green) (Calcium Fluoride (CaF2)) — mineral

Fluorite (Green)

Calcium Fluoride (CaF2)

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

Milky Quartz (Vein Quartz)

Silicon Dioxide (SiO2)

mineral
Conglomerate (or Breccia) (Clastic Sedimentary Rock) — sedimentary

Conglomerate (or Breccia)

Clastic Sedimentary Rock

sedimentary
Jasper Chert Nodules (Silicon Dioxide (SiO2) with Hematite impurities) — sedimentary

Jasper Chert Nodules

Silicon Dioxide (SiO2) with Hematite impurities

sedimentary
Sandstone (likely Graywacke or Lithic Sandstone) (Clastic Sedimentary Rock) — sedimentary

Sandstone (likely Graywacke or Lithic Sandstone)

Clastic Sedimentary Rock

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

Milky Quartz

Silicon Dioxide (SiO2)

mineral
Lunar Highlands Breccia (Meteorite) (Lunar Feldspathic Breccia) — igneous

Lunar Highlands Breccia (Meteorite)

Lunar Feldspathic Breccia

igneous
Tektite (Tektite (Amorphous silica rich glass)) — mineral

Tektite

Tektite (Amorphous silica rich glass)

mineral
Shale (Shale (Lutite)) — sedimentary

Shale

Shale (Lutite)

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

Tumbled Green Jasper

Silicon Dioxide (SiO2) with mineral inclusions

sedimentary
Garnet Schist (Almandine Garnet Schist) — metamorphic

Garnet Schist

Almandine Garnet Schist

metamorphic
Sandstone (Arenite (SiO2 based with primary clasts 0.0625 to 2 mm)) — sedimentary

Sandstone

Arenite (SiO2 based with primary clasts 0.0625 to 2 mm)

sedimentary
Quartz (with inclusions / Sandstone fragment) (Silicon Dioxide (SiO2)) — mineral

Quartz (with inclusions / Sandstone fragment)

Silicon Dioxide (SiO2)

mineral
Greenstone Porphyry (Porphyritic Metavolcanic Rock) — igneous

Greenstone Porphyry

Porphyritic Metavolcanic Rock

igneous
Sandstone (Arenite) — sedimentary

Sandstone

Arenite

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

Chalcedony (Agate/Quartz)

Silicon Dioxide (SiO2)

mineral