Rock Identifier

Category

Organic (Often Found By Beachcombers)

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

Celadonite in Basalt (Green Earth) (Celadonite (K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2)) — mineral

Celadonite in Basalt (Green Earth)

Celadonite (K(Mg,Fe2+)(Fe3+,Al)Si4O10(OH)2)

Iron-stained Quartz (Silicon Dioxide with Hematite/Limonite impurities (SiO2 + Fe2O3)) — mineral

Iron-stained Quartz

Silicon Dioxide with Hematite/Limonite impurities (SiO2 + Fe2O3)

Serpentinite (Commonly known as Serpentine) (Antigorite, Lizardite, or Chrysotile [(Mg,Fe)3Si2O5(OH)4]) — metamorphic

Serpentinite (Commonly known as Serpentine)

Antigorite, Lizardite, or Chrysotile [(Mg,Fe)3Si2O5(OH)4]

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Limestone (specifically Grainstone or Micrite) (Calcium Carbonate (CaCO3)) — sedimentary

Limestone (specifically Grainstone or Micrite)

Calcium Carbonate (CaCO3)

Granite Pebble (Granite (Phaneritic intrusive igneous rock)) — igneous

Granite Pebble

Granite (Phaneritic intrusive igneous rock)

Biotite Schist (Biotite Schist) — Metamorphic

Biotite Schist

Biotite Schist

Aquamarine (Aquamarine (Beryl variety) - Be3Al2(Si6O18)) — mineral

Aquamarine

Aquamarine (Beryl variety) - Be3Al2(Si6O18)

Rose Quartz (Rose Quartz (SiO2 with traces of Ti, Fe, or Mn)) — mineral

Rose Quartz

Rose Quartz (SiO2 with traces of Ti, Fe, or Mn)

Dalmatian Jasper (Peralkaline rhyolite with Arfvedsonite inclusions) — igneous

Dalmatian Jasper

Peralkaline rhyolite with Arfvedsonite inclusions

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

Quartz (Chert/Chalcedony variety)

Silicon Dioxide (SiO2)

Fossiliferous Limestone (Chertified Limestone) (Calcium Carbonate (CaCO3) often replaced by Microcrystalline Silica (SiO2)) — sedimentary

Fossiliferous Limestone (Chertified Limestone)

Calcium Carbonate (CaCO3) often replaced by Microcrystalline Silica (SiO2)

Quartz (SiO₂ (Silicon Dioxide)) — Mineral

Quartz

SiO₂ (Silicon Dioxide)

Eclogite (Eclogite (Pyrope garnet and Omphacite pyroxene)) — metamorphic

Eclogite

Eclogite (Pyrope garnet and Omphacite pyroxene)

Sandstone (Arenite (SiO2 based with various cements)) — sedimentary

Sandstone

Arenite (SiO2 based with various cements)

Quartz (Rock Crystal) (Silicon Dioxide (SiO2)) — mineral

Quartz (Rock Crystal)

Silicon Dioxide (SiO2)

Limonite / Ironstone Nodule (Limonite (Hydrated iron(III) oxide-hydroxide), FeO(OH)·nH2O) — mineral

Limonite / Ironstone Nodule

Limonite (Hydrated iron(III) oxide-hydroxide), FeO(OH)·nH2O

Red Sandstone (Arenite (primarily Quartz SiO₂ with Hematite Fe₂O₃ staining)) — sedimentary

Red Sandstone

Arenite (primarily Quartz SiO₂ with Hematite Fe₂O₃ staining)

Red Garnet (Almandine Garnet (Fe3Al2(SiO4)3)) — mineral

Red Garnet

Almandine Garnet (Fe3Al2(SiO4)3)

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

Chert (Chalcedony/Agate)

Microcrystalline Quartz (SiO2)

Quartzite Pebble (Quartzite (composed primarily of Silica, SiO2)) — metamorphic

Quartzite Pebble

Quartzite (composed primarily of Silica, SiO2)

Sandstone Concretion (Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)) — sedimentary

Sandstone Concretion

Ferruginous Sandstone Concretion (Primarily SiO2 with Iron Oxide cement)

Grey Agate (Silicon Dioxide (SiO2) - Variety of Chalcedony) — mineral

Grey Agate

Silicon Dioxide (SiO2) - Variety of Chalcedony

Septarian Nodule (Septarian Nodule (Calcite-filled Concretion)) — sedimentary

Septarian Nodule

Septarian Nodule (Calcite-filled Concretion)

Olivine (Peridot when gem-quality) (Olivine Group (Magnesium Iron Silicate, (Mg,Fe)2SiO4)) — mineral

Olivine (Peridot when gem-quality)

Olivine Group (Magnesium Iron Silicate, (Mg,Fe)2SiO4)

Sandstone (Quartzose) (Arenite (primarily SiO2)) — sedimentary

Sandstone (Quartzose)

Arenite (primarily SiO2)

Raw Corundum (Sapphire/Ruby variant) (Aluminum oxide (Al2O3)) — mineral

Raw Corundum (Sapphire/Ruby variant)

Aluminum oxide (Al2O3)

Magnetite / Iron Ore (Magnetite (Fe3O4)) — mineral

Magnetite / Iron Ore

Magnetite (Fe3O4)

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

Chert (Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Vesicular Basalt (Extrusive Basalt (Mafic Silicate)) — igneous

Vesicular Basalt

Extrusive Basalt (Mafic Silicate)

Yellow Jasper (Silicon Dioxide (SiO2) with Goethite/Iron Oxide inclusions) — sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) with Goethite/Iron Oxide inclusions

Sandstone (Ferruginous) (Arenite (primarily SiO2 with iron oxide cement)) — sedimentary

Sandstone (Ferruginous)

Arenite (primarily SiO2 with iron oxide cement)

Sandstone (Red Sandstone / River Stone) (Arenite (composed primarily of Quartz, SiO2, with Iron Oxide cementation)) — sedimentary

Sandstone (Red Sandstone / River Stone)

Arenite (composed primarily of Quartz, SiO2, with Iron Oxide cementation)

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

Carnelian (Chalcedony)

Silicon Dioxide (SiO2)

Nephrite Jade (Ca2(Mg,Fe)5Si8O22(OH)2) — metamorphic

Nephrite Jade

Ca2(Mg,Fe)5Si8O22(OH)2

Lapis Lazuli (Lapis Lazuli (Rock containing Lazurite, Na8[AlSi O4]6[S,Cl,SO4,OH]2)) — metamorphic

Lapis Lazuli

Lapis Lazuli (Rock containing Lazurite, Na8[AlSi O4]6[S,Cl,SO4,OH]2)

Red Sandstone (Arenite (primarily Quartz with Iron Oxide)) — sedimentary

Red Sandstone

Arenite (primarily Quartz with Iron Oxide)

Sandstone (Arenite (SiO2 based)) — sedimentary

Sandstone

Arenite (SiO2 based)

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

Quartz (Milky/Common)

Quartz (Silicon Dioxide, SiO2)

Siltstone with Weathering Rind (Siltstone (composed of microscopic quartz and clay minerals)) — sedimentary

Siltstone with Weathering Rind

Siltstone (composed of microscopic quartz and clay minerals)

Milky Quartz in Matrix (Silicon Dioxide (SiO2)) — mineral

Milky Quartz in Matrix

Silicon Dioxide (SiO2)

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

Yellow Chalcedony (Agate)

Silicon Dioxide (SiO2)