Rock Identifier

Category

Organic (Often Found By Beachcombers)

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

Sandstone (clastic) (Clastic Sedimentary Rock (primarily composed of SiO2)) — sedimentary

Sandstone (clastic)

Clastic Sedimentary Rock (primarily composed of SiO2)

Milky Quartz with inclusions (Quartz (Silicon Dioxide, SiO2)) — mineral

Milky Quartz with inclusions

Quartz (Silicon Dioxide, SiO2)

Stream Pebble (Basalt/Greywacke) (Mafic Igneous Rock (Fine-grained)) — igneous

Stream Pebble (Basalt/Greywacke)

Mafic Igneous Rock (Fine-grained)

Green Aventurine (Silicon Dioxide (SiO2) with Fuchsite inclusions) — metamorphic

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Porphyritic Rhyolite (Rhyolite (Porphyritic)) — igneous

Porphyritic Rhyolite

Rhyolite (Porphyritic)

Chert (Iron-stained) (Chert (Cryptocrystalline Silica, SiO2)) — sedimentary

Chert (Iron-stained)

Chert (Cryptocrystalline Silica, SiO2)

Sandstone (Arenite (SiO2 primarily)) — sedimentary

Sandstone

Arenite (SiO2 primarily)

Cloudy Quartz / Quartz Tumble (Silicon Dioxide (SiO2)) — mineral

Cloudy Quartz / Quartz Tumble

Silicon Dioxide (SiO2)

Amethyst Quartz (Silicon Dioxide (SiO2) with iron impurities) — mineral

Amethyst Quartz

Silicon Dioxide (SiO2) with iron impurities

Gold Nugget (Native Gold (Au)) — mineral

Gold Nugget

Native Gold (Au)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Limonite (Iron Ore) (Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)) — mineral

Limonite (Iron Ore)

Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)·nH2O)

Carnelian Agate (Chalcedony (SiO2 with Iron Oxide impurities)) — mineral

Carnelian Agate

Chalcedony (SiO2 with Iron Oxide impurities)

Chert (Yellow Jasper variant) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Yellow Jasper variant)

Silicon Dioxide (SiO2)

Sandstone with Liesegang Rings (Arenite with Iron Oxide Concretions) — sedimentary

Sandstone with Liesegang Rings

Arenite with Iron Oxide Concretions

Sandstone (with Iron Staining) (Clastic sedimentary rock (primarily Quartz with Hematite/Limonite oxides)) — sedimentary

Sandstone (with Iron Staining)

Clastic sedimentary rock (primarily Quartz with Hematite/Limonite oxides)

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

Rose Quartz

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

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

Jasper pebble

Jasper (Silicon Dioxide, SiO2)

Fluorite (Fluorite (Calcium Fluoride, CaF2)) — Mineral

Fluorite

Fluorite (Calcium Fluoride, CaF2)

Quartzite Pebble (Metamorphosed Quartz Sandstone (SiO2)) — metamorphic

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Granite Cobble (Granite (Phaneritic Quartz-Feldspar Felsic Rock)) — igneous

Granite Cobble

Granite (Phaneritic Quartz-Feldspar Felsic Rock)

Schorl (Black Tourmaline) (Schorl (Sodium Iron Aluminum Borosilicate Hydroxide), NaFe3Al6(BO3)3Si6O18(OH)4) — mineral

Schorl (Black Tourmaline)

Schorl (Sodium Iron Aluminum Borosilicate Hydroxide), NaFe3Al6(BO3)3Si6O18(OH)4

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Diorite (River Cobble) (Phaneritic Intermediate Plutonic Rock) — igneous

Diorite (River Cobble)

Phaneritic Intermediate Plutonic Rock

Quartz (Quartz (SiO₂)) — Mineral

Quartz

Quartz (SiO₂)

Smoky Quartz (Tumbled) (Silicon Dioxide (SiO2)) — mineral

Smoky Quartz (Tumbled)

Silicon Dioxide (SiO2)

Greenstone (Epidosite or Altered Basalt) (Epidosite (Ca2(Al, Fe)3(SiO4)3(OH))) — metamorphic

Greenstone (Epidosite or Altered Basalt)

Epidosite (Ca2(Al, Fe)3(SiO4)3(OH))

Quartzite (River Pebble) (Quartzite (primarily SiO2)) — metamorphic

Quartzite (River Pebble)

Quartzite (primarily SiO2)

Quartzite Pebble (Metamorphosed Quartz Sandstone (SiO2)) — metamorphic

Quartzite Pebble

Metamorphosed Quartz Sandstone (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Chert (with Quartz Vein) (Microcrystalline silica (SiO2)) — sedimentary

Chert (with Quartz Vein)

Microcrystalline silica (SiO2)

Quartz with Iron Staining (Silicon Dioxide (SiO2)) — mineral

Quartz with Iron Staining

Silicon Dioxide (SiO2)

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

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Pink Granite (Phaneritic Felsic Igneous Rock (Rich in K-Feldspar)) — igneous

Pink Granite

Phaneritic Felsic Igneous Rock (Rich in K-Feldspar)

Basalt (Basalt) — igneous

Basalt

Basalt

Red Jasper (Silicon dioxide (SiO2) with iron oxide inclusions) — mineral

Red Jasper

Silicon dioxide (SiO2) with iron oxide inclusions

Muscovite Mica (Golden/Yellow variety) (KAl2(AlSi3O10)(F,OH)2) — mineral

Muscovite Mica (Golden/Yellow variety)

KAl2(AlSi3O10)(F,OH)2

Ruby (Corundum (Al2O3 with Chromium traces)) — mineral

Ruby

Corundum (Al2O3 with Chromium traces)

Sandstone Concretion (Clastic sedimentary rock (primarily Silica, SiO2, or Calcium Carbonate, CaCO3)) — sedimentary

Sandstone Concretion

Clastic sedimentary rock (primarily Silica, SiO2, or Calcium Carbonate, CaCO3)

Chert (specifically Flint or Jasper variant) (Silicon Dioxide (SiO2)) — sedimentary

Chert (specifically Flint or Jasper variant)

Silicon Dioxide (SiO2)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Blue Slag Glass (Amorphous Silica (Industrial byproduct)) — Antropogenic (Man-made glass byproduct)

Blue Slag Glass

Amorphous Silica (Industrial byproduct)

Antropogenic (Man-made glass byproduct)