Rock Identifier

Category

Organic (Often Found By Beachcombers)

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

Red Jasper (Jasper (a variety of Chalcedony, SiO₂ with impurities)) — Mineral

Red Jasper

Jasper (a variety of Chalcedony, SiO₂ with impurities)

Quartzite Pebble (Metamorphic Quartzite (SiO2)) — metamorphic

Quartzite Pebble

Metamorphic Quartzite (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Sandstone (Weathered Pebble) (Arenite (primarily SiO2)) — sedimentary

Sandstone (Weathered Pebble)

Arenite (primarily SiO2)

Ironstone Concretion (Siderite Nodules) (Siderite (FeCO3) in Mudstone or Sandstone matrix) — sedimentary

Ironstone Concretion (Siderite Nodules)

Siderite (FeCO3) in Mudstone or Sandstone matrix

Sandstone (Arenite) — sedimentary

Sandstone

Arenite

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Obsidian (Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)) — igneous

Obsidian

Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)

Sea Glass (Amorphous Silica (SiO2) with various additives) — Mineraloid (Anthropogenic)

Sea Glass

Amorphous Silica (SiO2) with various additives

Mineraloid (Anthropogenic)

Stromatolite (Stromatolite (Cyanobacteria-formed Organo-sedimentary structure)) — sedimentary

Stromatolite

Stromatolite (Cyanobacteria-formed Organo-sedimentary structure)

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

Serpentine

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

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

Chert (Nodule)

Microcrystalline Silica (SiO2)

Quartzite Pebble (Quartzite (primarily SiO2)) — metamorphic

Quartzite Pebble

Quartzite (primarily SiO2)

Rough Green Calcite (Calcite (Calcium Carbonate, CaCO3)) — mineral

Rough Green Calcite

Calcite (Calcium Carbonate, CaCO3)

Chert (also known as Flint or Common Chalcedony) (Cryptocrystalline Silica (SiO2)) — sedimentary

Chert (also known as Flint or Common Chalcedony)

Cryptocrystalline Silica (SiO2)

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

Amethyst

Silicon Dioxide (SiO2) with iron impurities

Gold Flakes in Oil (Novelty Specimen) (Native Gold (Au)) — mineral

Gold Flakes in Oil (Novelty Specimen)

Native Gold (Au)

Green Calcite (Calcium Carbonate (CaCO3)) — mineral

Green Calcite

Calcium Carbonate (CaCO3)

Chert (Black Flint) (Chert (Microcrystalline Quartz, SiO2)) — sedimentary

Chert (Black Flint)

Chert (Microcrystalline Quartz, SiO2)

Gold Nugget (Placer Gold) (Native Gold (Au)) — mineral

Gold Nugget (Placer Gold)

Native Gold (Au)

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

Orange Quartzite / River Pebble

Quartzite (primarily SiO2)

Aventurine (Quartz (Aventurine variety)) — Mineral

Aventurine

Quartz (Aventurine variety)

Limestone (Calcareous sedimentary rock (primarily CaCO3)) — sedimentary

Limestone

Calcareous sedimentary rock (primarily CaCO3)

Red Quartzite River Stone (Metamorphic Rock (composed mainly of Quartz, SiO2)) — metamorphic

Red Quartzite River Stone

Metamorphic Rock (composed mainly of Quartz, SiO2)

Jasper (Red Jasper) (Silicon Dioxide (SiO2) with Hematite inclusions) — sedimentary

Jasper (Red Jasper)

Silicon Dioxide (SiO2) with Hematite inclusions

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Citrine (likely Heat-Treated) (Quartz (Silicon Dioxide, SiO2)) — mineral

Citrine (likely Heat-Treated)

Quartz (Silicon Dioxide, SiO2)

Iron-Nickel Meteorite (Possible Chondrite or Oxidized Iron) (Siderite (Nickel-Iron) or Chondrite (Si/Fe composite)) — igneous

Iron-Nickel Meteorite (Possible Chondrite or Oxidized Iron)

Siderite (Nickel-Iron) or Chondrite (Si/Fe composite)

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

Chert (Flint)

Silicon Dioxide (SiO2)

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

Green Jade (specifically Nephrite)

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

Sandstone (likely Siltstone or Mudstone variety) (Clastic Sedimentary Rock (primarily SiO2 with iron oxides)) — sedimentary

Sandstone (likely Siltstone or Mudstone variety)

Clastic Sedimentary Rock (primarily SiO2 with iron oxides)

Milky Quartz with Country Rock contact (Silicon Dioxide (SiO2) in contact with Metamorphic/Igneous rock) — mineral

Milky Quartz with Country Rock contact

Silicon Dioxide (SiO2) in contact with Metamorphic/Igneous rock

Sodalite (Na8(Al6Si6O24)Cl2 (Sodium Aluminum Silicate Chloride)) — mineral

Sodalite

Na8(Al6Si6O24)Cl2 (Sodium Aluminum Silicate Chloride)

Stichtite in Serpentine (Atlantasite) (Mg6Cr2CO3(OH)16·4H2O in Mg3Si2O5(OH)4) — metamorphic

Stichtite in Serpentine (Atlantasite)

Mg6Cr2CO3(OH)16·4H2O in Mg3Si2O5(OH)4

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

Chert (Jasper/Agate variety)

Microcrystalline quartz (SiO2)

Quartzite with Quartz Geode / Vug (Crystalline Silicon Dioxide (SiO2) in Metamorphic Host) — metamorphic

Quartzite with Quartz Geode / Vug

Crystalline Silicon Dioxide (SiO2) in Metamorphic Host

Limonite (Iron Stone) (Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O) — mineral

Limonite (Iron Stone)

Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O

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

Quartzite River Pebble

Quartzite (primarily SiO2)

Quartz Pebble (Silicon Dioxide (SiO2)) — mineral

Quartz Pebble

Silicon Dioxide (SiO2)

Gold Nugget (Native Gold (Au)) — mineral

Gold Nugget

Native Gold (Au)

Tiger's Eye (Mineral Collection) (Tiger's Eye (SiO2 with crocidolite inclusions)) — mineral

Tiger's Eye (Mineral Collection)

Tiger's Eye (SiO2 with crocidolite inclusions)

Slag (Anthropogenic Vitrification Product / Silicate Slag) — Anthropogenic (Man-made industrial byproduct)

Slag

Anthropogenic Vitrification Product / Silicate Slag

Anthropogenic (Man-made industrial byproduct)