Rock Identifier

Category

Organic (Often Found By Beachcombers)

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

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Arsenopyrite with Quartz (Arsenopyrite (FeAsS)) — mineral

Arsenopyrite with Quartz

Arsenopyrite (FeAsS)

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

Limonite (Iron Stone Concretion)

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

Agate (Agate (a variety of Chalcedony, SiO2)) — Mineral

Agate

Agate (a variety of Chalcedony, SiO2)

Sea Bean (Hamburger Bean) (Mucuna sloanei) — organic/biological specimen

Sea Bean (Hamburger Bean)

Mucuna sloanei

organic/biological specimen

Howlite (Howlite (Calcium borosilicate hydroxide, Ca2B5SiO9(OH)5)) — mineral

Howlite

Howlite (Calcium borosilicate hydroxide, Ca2B5SiO9(OH)5)

Quartzite (Quartzite (SiO2)) — metamorphic

Quartzite

Quartzite (SiO2)

Bivalve Shell (Fossil or Contemporary) (Class Bivalvie (various genera and species of clams, cockles, etc.)) — Sedimentary (Biogenic sediment or biological remain)

Bivalve Shell (Fossil or Contemporary)

Class Bivalvie (various genera and species of clams, cockles, etc.)

Sedimentary (Biogenic sediment or biological remain)

Gneiss (Gneiss) — metamorphic

Gneiss

Gneiss

Slag (Industrial Glass) (Artificial Vitreous Silicate) — mineraloid (anthropogenic)

Slag (Industrial Glass)

Artificial Vitreous Silicate

mineraloid (anthropogenic)

Picture Jasper (Silicon dioxide (SiO2)) — sedimentary

Picture Jasper

Silicon dioxide (SiO2)

Limonite (often after Hematite or Goethite) (Limonite (FeO(OH)·nH2O)) — mineral

Limonite (often after Hematite or Goethite)

Limonite (FeO(OH)·nH2O)

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)

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

Chert (Flint)

Microcrystalline Quartz (SiO2)

Micaceous Rock (likely Muscovite Schist/Gneiss or a Muscovite-rich Specimen) (Predominantly Muscovite (KAl2(AlSi3O10)(F,OH)2), often found in rocks like Muscovite Schist or Muscovite Gneiss.) — Metamorphic, Mineral (within a rock type)

Micaceous Rock (likely Muscovite Schist/Gneiss or a Muscovite-rich Specimen)

Predominantly Muscovite (KAl2(AlSi3O10)(F,OH)2), often found in rocks like Muscovite Schist or Muscovite Gneiss.

Metamorphic, Mineral (within a rock type)

Rose Quartz (Quartz (SiO₂), variety Rose Quartz) — Mineral

Rose Quartz

Quartz (SiO₂), variety Rose Quartz

Howlite (Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)) — Mineral

Howlite

Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)

Sodalite (Sodalite (Na8Al6Si6O24Cl2)) — mineral

Sodalite

Sodalite (Na8Al6Si6O24Cl2)

Quartzite (SiO2 (Silicon Dioxide)) — metamorphic

Quartzite

SiO2 (Silicon Dioxide)

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

Chert (Flint Nobule)

Silicon Dioxide (SiO2)

Concrete / Anthropogenic Conglomerate (Man-made composite material (Portland cement, aggregate, and water)) — not a natural rock

Concrete / Anthropogenic Conglomerate

Man-made composite material (Portland cement, aggregate, and water)

not a natural rock

Slag (Metallurgical by-product) — Anthropogenic (Man-made material)

Slag

Metallurgical by-product

Anthropogenic (Man-made material)

Granodiorite (or Granite) Pebble (Phaneritic Felsic Igneous Pebble) — igneous

Granodiorite (or Granite) Pebble

Phaneritic Felsic Igneous Pebble

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

Sandstone (Quartzose)

Arenite (SiO2 principal)

Quartzite (Metamorphic Quartz (SiO2)) — metamorphic

Quartzite

Metamorphic Quartz (SiO2)

Malachite Coating on Host Rock (Malachite [Cu2CO3(OH)2]) — mineral

Malachite Coating on Host Rock

Malachite [Cu2CO3(OH)2]

Yellow Jasper (Silicon Dioxide (SiO2) with iron inclusions) — sedimentary

Yellow Jasper

Silicon Dioxide (SiO2) with iron inclusions

Coal (specifically Bituminous or Anthracite) (Organic sedimentary rock; primarily Carbon (C) with varying H, S, O, N) — sedimentary

Coal (specifically Bituminous or Anthracite)

Organic sedimentary rock; primarily Carbon (C) with varying H, S, O, N

Quartzite Pebble (Quartzite (SiO2)) — metamorphic

Quartzite Pebble

Quartzite (SiO2)

French Bulldog (Blue Variety) (Canis lupus familiaris) — Organic (Biological Organism)

French Bulldog (Blue Variety)

Canis lupus familiaris

Organic (Biological Organism)

Chrysocolla (Hydrated copper silicate (Cu,Al)2H2Si2O5(OH)4·nH2O) — mineral

Chrysocolla

Hydrated copper silicate (Cu,Al)2H2Si2O5(OH)4·nH2O

Venetian Gold Granite (Phaneritic Felsic Igneous Rock (Granite)) — igneous

Venetian Gold Granite

Phaneritic Felsic Igneous Rock (Granite)

Quartzite (Quartzite (primarily SiO2)) — metamorphic

Quartzite

Quartzite (primarily SiO2)

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

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Black Sapphire (Basaltic Blue Sapphire) (Corundum (Al2O3)) — mineral

Black Sapphire (Basaltic Blue Sapphire)

Corundum (Al2O3)

Psilomelane (Black Hematite/Manganese Ore) (Barium Manganese Oxide (Formula: BaMn9O18(OH)4)) — mineral

Psilomelane (Black Hematite/Manganese Ore)

Barium Manganese Oxide (Formula: BaMn9O18(OH)4)

Quartz (Quartz (SiO₂ - Silicon Dioxide)) — Mineral

Quartz

Quartz (SiO₂ - Silicon Dioxide)

Limonite (Iron Ore) (Limonite (FeO(OH)·nH2O)) — mineral

Limonite (Iron Ore)

Limonite (FeO(OH)·nH2O)

Sandstone Concretion (Moqui Marble / Iron-oxide Concretion (SiO2 with Hematite/Goethite)) — sedimentary

Sandstone Concretion

Moqui Marble / Iron-oxide Concretion (SiO2 with Hematite/Goethite)

Gold-bearing Quartz with Pyrite (Quartz (SiO2) with Gold (Au) and Pyrite (FeS2)) — mineral

Gold-bearing Quartz with Pyrite

Quartz (SiO2) with Gold (Au) and Pyrite (FeS2)

Chert (Yellow Jasper variant) (Microcrystalline Quartz (SiO2)) — sedimentary

Chert (Yellow Jasper variant)

Microcrystalline Quartz (SiO2)

Malachite (Copper carbonate hydroxide [Cu2CO3(OH)2]) — mineral

Malachite

Copper carbonate hydroxide [Cu2CO3(OH)2]