Rock Identifier

Category

Organic (Often Found By Beachcombers)

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

Satin Spar (often marketed as Selenite) (Fibrous Gypsum (CaSO4·2H2O)) — mineral

Satin Spar (often marketed as Selenite)

Fibrous Gypsum (CaSO4·2H2O)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Jasper (Iron-stained) (Silicon Dioxide (SiO2) with iron oxide inclusions) — sedimentary

Jasper (Iron-stained)

Silicon Dioxide (SiO2) with iron oxide inclusions

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

Quartz (Vein Quartz)

Silicon Dioxide (SiO2)

Pet Rock (Man-made Quartzite or Granite Cobble) (Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica) — igneous or metamorphic (base stone); anthropogenic (decoration)

Pet Rock (Man-made Quartzite or Granite Cobble)

Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica

igneous or metamorphic (base stone); anthropogenic (decoration)

Painted Garden Rock (likely Granite or Limestone base) (Silicon Dioxide (SiO2) / Calcium Carbonate (CaCO3) based substrate with Acrylic/Enamel pigments) — igneous or sedimentary (anthropogenic modification)

Painted Garden Rock (likely Granite or Limestone base)

Silicon Dioxide (SiO2) / Calcium Carbonate (CaCO3) based substrate with Acrylic/Enamel pigments

igneous or sedimentary (anthropogenic modification)

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

Sandstone (Painted)

Arenite (primarily SiO2)

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

Sandstone (Quartzose Sandstone)

Arenite (SiO2 primarily)

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

Milky Quartz with Iron Staining

Quartz (Silicon Dioxide, SiO2)

Sandstone (Arenite (SiO2 primarily)) — sedimentary

Sandstone

Arenite (SiO2 primarily)

Banded Agate (Cryptocrystalline Silica (SiO2)) — mineral

Banded Agate

Cryptocrystalline Silica (SiO2)

Quartz (Silicon Dioxide (SiO2)) — mineral

Quartz

Silicon Dioxide (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Sandstone (Ferruginous) (Sandstone (primarily SiO2 with Iron Oxide cement)) — sedimentary

Sandstone (Ferruginous)

Sandstone (primarily SiO2 with Iron Oxide cement)

Sandstone (Quartzose Sandstone) (Clastic Sedimentary Rock (primarily SiO2)) — sedimentary

Sandstone (Quartzose Sandstone)

Clastic Sedimentary Rock (primarily SiO2)

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

Sandstone (Quartzose)

Arenite (primarily SiO2)

Yellow Jasper (Chalcedony (SiO2) with iron oxide inclusions) — mineral

Yellow Jasper

Chalcedony (SiO2) with iron oxide inclusions

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

Chert (Nodule)

Silicon Dioxide (SiO2)

Moonstone with Black Tourmaline (Orthoclase (KAlSi3O8) with Schorl inclusions (NaFe3Al6(BO3)3Si6O18(OH)4)) — mineral

Moonstone with Black Tourmaline

Orthoclase (KAlSi3O8) with Schorl inclusions (NaFe3Al6(BO3)3Si6O18(OH)4)

Quartz (Quartz (SiO₂)) — Mineral

Quartz

Quartz (SiO₂)

Granite (Granite (a felsic intrusive igneous rock)) — Igneous rock

Granite

Granite (a felsic intrusive igneous rock)

Barite (Barium Sulfate (BaSO4)) — mineral

Barite

Barium Sulfate (BaSO4)

Jasper / Chert (River Pebble) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Jasper / Chert (River Pebble)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (Nodule) (Silicon Dioxide (SiO2) - Microcrystalline Quartz) — sedimentary

Chert (Nodule)

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Quartzite Pebble (Quartzite (primarily SiO2)) — metamorphic

Quartzite Pebble

Quartzite (primarily SiO2)

Titanium Coated Aura Quartz (Apple Aura Quartz) (Silicon Dioxide (SiO2) with Metallic Vapor Deposition Coating) — Mineral (Man-modified)

Titanium Coated Aura Quartz (Apple Aura Quartz)

Silicon Dioxide (SiO2) with Metallic Vapor Deposition Coating

Mineral (Man-modified)

Grey Jasper (Tumbled Quartz variant) (Jasper (Silicon Dioxide, SiO2)) — sedimentary

Grey Jasper (Tumbled Quartz variant)

Jasper (Silicon Dioxide, SiO2)

Picture Jasper (Silicon Dioxide (SiO2) with mineral inclusions) — sedimentary

Picture Jasper

Silicon Dioxide (SiO2) with mineral inclusions

Yellow Agate (Silicon Dioxide (SiO2)) — mineral

Yellow Agate

Silicon Dioxide (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Eclogite garnet in matrix (Eclogite (Garnet-Omphacite rock)) — metamorphic

Eclogite garnet in matrix

Eclogite (Garnet-Omphacite rock)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Sandstone (likely Arkose) (Arenite (Feldspathic Sandstone / Arkose)) — sedimentary

Sandstone (likely Arkose)

Arenite (Feldspathic Sandstone / Arkose)

Ammonite Fossil (Polished Half) (Ammonoidea (subclass)) — sedimentary

Ammonite Fossil (Polished Half)

Ammonoidea (subclass)

Cullet Glass (Man-made Glass Slag) (Amorphous Silica (SiO2) with chemical additives) — Mineraloid

Cullet Glass (Man-made Glass Slag)

Amorphous Silica (SiO2) with chemical additives

Red Garnet (Pyrope or Almandine (Silicate group, X3Y2(SiO4)3)) — Mineral

Red Garnet

Pyrope or Almandine (Silicate group, X3Y2(SiO4)3)

Fluorite (Calcium Fluoride (CaF2)) — mineral

Fluorite

Calcium Fluoride (CaF2)

Mahogany Obsidian (Volcanic Glass (predominantly SiO2 with inclusions of Hematite or Magnetite)) — igneous

Mahogany Obsidian

Volcanic Glass (predominantly SiO2 with inclusions of Hematite or Magnetite)

Iolite-bearing Gneiss (Cordierite) (Cordierite (Mg2Al4Si5O18) in Gneiss matrix) — metamorphic

Iolite-bearing Gneiss (Cordierite)

Cordierite (Mg2Al4Si5O18) in Gneiss matrix

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

Jasper

Jasper (Silicon Dioxide, SiO2)

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

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Limestone (Calcareous sedimentary rock (CaCO3)) — sedimentary

Limestone

Calcareous sedimentary rock (CaCO3)