Rock Identifier

Category

Organic (Often Found By Beachcombers)

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

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

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Fuchsite (Green Muscovite in Quartz) (Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)) — metamorphic

Fuchsite (Green Muscovite in Quartz)

Chromium-rich Muscovite (K(Al,Cr)2(AlSi3O10)(OH)2)

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

Rhodonite (Manganese Silicate (Mn,Fe,Mg,Ca)SiO3) — mineral

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Greenstone (Rough Jadeite or Nephrite) (Sodium aluminum silicate (Jadeite) / Calcium magnesium iron silicate (Nephrite)) — metamorphic

Greenstone (Rough Jadeite or Nephrite)

Sodium aluminum silicate (Jadeite) / Calcium magnesium iron silicate (Nephrite)

Rhodonite (Manganese Silicate (Mn,Fe,Mg,Ca)SiO3) — mineral

Rhodonite

Manganese Silicate (Mn,Fe,Mg,Ca)SiO3

Chert (Tripolitic Chert / Flint Nodules) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Tripolitic Chert / Flint Nodules)

Microcrystalline Quartz (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Pyromorphite on Epidote (Pyromorphite [Pb5(PO4)3Cl] and Epidote [Ca2(Al2,Fe3+)(SiO4)3(OH)]) — mineral

Pyromorphite on Epidote

Pyromorphite [Pb5(PO4)3Cl] and Epidote [Ca2(Al2,Fe3+)(SiO4)3(OH)]

Tiger's Eye (Pseudomorph of Quartz after Crocidolite (SiO2)) — mineral

Tiger's Eye

Pseudomorph of Quartz after Crocidolite (SiO2)

Aquamarine and clear quartz (Aquamarine (Be3Al2Si6O18), Quartz (SiO2)) — Mineral

Aquamarine and clear quartz

Aquamarine (Be3Al2Si6O18), Quartz (SiO2)

Yellow Quartzite (Silicon Dioxide (SiO2)) — metamorphic

Yellow Quartzite

Silicon Dioxide (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Amazonite (Amazonite (K(AlSi3O8))) — mineral

Amazonite

Amazonite (K(AlSi3O8))

Basalt (Basalt (Extrusive Mafic Igneous)) — igneous

Basalt

Basalt (Extrusive Mafic Igneous)

Sandstone (Arenite (SiO2 predominantly)) — sedimentary

Sandstone

Arenite (SiO2 predominantly)

Blue Moss Agate / Blue Chalcedony (Silicon Dioxide (SiO2)) — mineral

Blue Moss Agate / Blue Chalcedony

Silicon Dioxide (SiO2)

Lepidolite (Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)) — mineral

Lepidolite

Lepidolite (K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2)

Milk Quartz (White Quartz) (Silicon Dioxide (SiO2)) — mineral

Milk Quartz (White Quartz)

Silicon Dioxide (SiO2)

Copper-bearing Quartz (likely Malachite on Quartz matrix) (Cu2CO3(OH)2 (Malachite) on SiO2 (Quartz)) — mineral

Copper-bearing Quartz (likely Malachite on Quartz matrix)

Cu2CO3(OH)2 (Malachite) on SiO2 (Quartz)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Gabbro (Gabbro (phaneritic mafic intrusive rock)) — Igneous

Gabbro

Gabbro (phaneritic mafic intrusive rock)

Crinaudite / Fossilized Crinoid Stem (Crinoid (Echinodermata) in a Calcitic/Siliceous Matrix) — sedimentary

Crinaudite / Fossilized Crinoid Stem

Crinoid (Echinodermata) in a Calcitic/Siliceous Matrix

Grey Agate (Tumbled) (Silicon Dioxide (SiO2)) — mineral

Grey Agate (Tumbled)

Silicon Dioxide (SiO2)

Smoky Quartz (Silicon Dioxide (SiO₂)) — mineral

Smoky Quartz

Silicon Dioxide (SiO₂)

Ironstone Concretion (Siderite or Ferruginous Concretion (FeCO3 or Iron Oxides)) — sedimentary

Ironstone Concretion

Siderite or Ferruginous Concretion (FeCO3 or Iron Oxides)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Black Tourmaline (Schorl) (Schorl (Na(Fe^2+)3Al6(Si6O18)(BO3)3)(OH)3(OH))) — mineral

Black Tourmaline (Schorl)

Schorl (Na(Fe^2+)3Al6(Si6O18)(BO3)3)(OH)3(OH))

Lapis Lazuli (Lapis Lazuli (a rock type, not a single mineral, composed primarily of lazurite, calcite, and pyrite)) — Mineral, part of a rock

Lapis Lazuli

Lapis Lazuli (a rock type, not a single mineral, composed primarily of lazurite, calcite, and pyrite)

Mineral, part of a rock

Fuchsite with Ruby (Cr-rich Muscovite with Corundum (K(Al,Cr)2(AlSi3O10)(OH)2)) — metamorphic

Fuchsite with Ruby

Cr-rich Muscovite with Corundum (K(Al,Cr)2(AlSi3O10)(OH)2)

Desert Rose (Gypsum/Baryte) (Hydrated Calcium Sulfate (CaSO4·2H2O)) — mineral

Desert Rose (Gypsum/Baryte)

Hydrated Calcium Sulfate (CaSO4·2H2O)

Blue Chalcedony (Cryptocrystalline Quartz (SiO2)) — mineral

Blue Chalcedony

Cryptocrystalline Quartz (SiO2)

Fossilized Coral (Petoskey Stone or similar) (Hexagonaria percarinata (Fossilized Rugose Coral)) — sedimentary

Fossilized Coral (Petoskey Stone or similar)

Hexagonaria percarinata (Fossilized Rugose Coral)

Ferruginous Quartz (Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions) — mineral

Ferruginous Quartz

Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions

Basalt Water-Worn Pebble (Aphanitic Mafic Igneous Rock) — igneous

Basalt Water-Worn Pebble

Aphanitic Mafic Igneous Rock

Limestone (Calcium Carbonate (CaCO3)) — sedimentary

Limestone

Calcium Carbonate (CaCO3)

Sandstone (Quartzite-rich) (Clastic sedimentary rock (primarily SiO2)) — sedimentary

Sandstone (Quartzite-rich)

Clastic sedimentary rock (primarily SiO2)

Asphalt (Road Aggregate) (Asphalt concrete / Bituminous mixture) — anthropogenic sedimentary (technolith)

Asphalt (Road Aggregate)

Asphalt concrete / Bituminous mixture

anthropogenic sedimentary (technolith)

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Green Fluorite (Calcium Fluoride (CaF2)) — mineral

Green Fluorite

Calcium Fluoride (CaF2)

Pallasite Meteorite (Pallasite (ST-class)) — mineral

Pallasite Meteorite

Pallasite (ST-class)