Rock Identifier

Category

Organic (Often Found By Beachcombers)

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

Limonite and Goethite (Limonite (hydrated iron(III) oxide-hydroxide) and Goethite (α-FeO(OH))) — mineral

Limonite and Goethite

Limonite (hydrated iron(III) oxide-hydroxide) and Goethite (α-FeO(OH))

Basalt (Extrusive mafic igneous rock) — igneous

Basalt

Extrusive mafic igneous rock

Basalt (with possible iron oxide staining) (Mafic Igneous Rock (primarily Plagioclase and Pyroxene)) — igneous

Basalt (with possible iron oxide staining)

Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

Slag (Anthropogenic glassy silicate) — Mineral-like byproduct

Slag

Anthropogenic glassy silicate

Mineral-like byproduct

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

Malachite

Copper carbonate hydroxide [Cu2CO3(OH)2]

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

Jasper

Jasper (Silicon Dioxide, SiO2)

Metaconglomerate (Protolith: Conglomerate (comprising SiO2, Al2O3, etc.)) — metamorphic

Metaconglomerate

Protolith: Conglomerate (comprising SiO2, Al2O3, etc.)

Quartz (Iron-Stained) (Silicon Dioxide (SiO2)) — mineral

Quartz (Iron-Stained)

Silicon Dioxide (SiO2)

Quartzite Pebble (Quartzite (mostly SiO2)) — metamorphic

Quartzite Pebble

Quartzite (mostly SiO2)

Azurite with Malachite and Limonite (Azurite Cu3(CO3)2(OH)2 / Malachite Cu2CO3(OH)2) — mineral

Azurite with Malachite and Limonite

Azurite Cu3(CO3)2(OH)2 / Malachite Cu2CO3(OH)2

Quartz / Quartzite Fragment (Silicon Dioxide (SiO2)) — mineral / metamorphic

Quartz / Quartzite Fragment

Silicon Dioxide (SiO2)

mineral / metamorphic

Granite (Phaneritic Felsic Intrusive Igneous Rock) — igneous

Granite

Phaneritic Felsic Intrusive Igneous Rock

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

Chert (Flint Nodules)

Silicon Dioxide (SiO2)

River Stone (River Pebbles) (Alluvial Deposit (typically Quartzite, Sandstone, or Granite clasts)) — sedimentary

River Stone (River Pebbles)

Alluvial Deposit (typically Quartzite, Sandstone, or Granite clasts)

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

Red Jasper (possibly)

Jasper (a variety of Chalcedony, SiO2)

Synthetic Costume Accessory (Non-Geological) (Polyester and Acrylic Fiber (Anthropogenic polymer)) — Synthetic / Man-made textile

Synthetic Costume Accessory (Non-Geological)

Polyester and Acrylic Fiber (Anthropogenic polymer)

Synthetic / Man-made textile

Sandstone (Arenite (Sedimentary Rock)) — sedimentary

Sandstone

Arenite (Sedimentary Rock)

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

Chert (Flint)

Silicon Dioxide (SiO2)

Quartz (Smoky/Milky variety) (Silicon Dioxide (SiO2)) — mineral

Quartz (Smoky/Milky variety)

Silicon Dioxide (SiO2)

Iron Slag (Anthropogenic Iron oxide/Silicate composite) — Mineral-like byproduct (Technogenic)

Iron Slag

Anthropogenic Iron oxide/Silicate composite

Mineral-like byproduct (Technogenic)

Pyrite (Iron Sulfide (FeS2)) — mineral

Pyrite

Iron Sulfide (FeS2)

Orange Calcite (Calcite (Calcium Carbonate - CaCO3)) — mineral

Orange Calcite

Calcite (Calcium Carbonate - CaCO3)

Limonite (Iron Ore/Hydrated Iron Oxide) (Limonite (mixture of FeO(OH)·nH₂O minerals, mainly Goethite, FeO(OH) and Lepidocrocite, FeO(OH))) — Mineral

Limonite (Iron Ore/Hydrated Iron Oxide)

Limonite (mixture of FeO(OH)·nH₂O minerals, mainly Goethite, FeO(OH) and Lepidocrocite, FeO(OH))

Gold Nuggest (Native Gold (Au)) — mineral

Gold Nuggest

Native Gold (Au)

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

Limonite (with Pyrite)

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

Orange Calcite (Mexican Onyx) (Calcium Carbonate (CaCO3)) — mineral

Orange Calcite (Mexican Onyx)

Calcium Carbonate (CaCO3)

Quartzite pebble (Metamorphic Quartzite (primarily SiO2)) — metamorphic

Quartzite pebble

Metamorphic Quartzite (primarily SiO2)

Basalt (Mafic Igneous Rock) — igneous

Basalt

Mafic Igneous Rock

Rose Quartz Beads (SiO2 (Silicon Dioxide with trace inclusions of Ti, Fe, or Mn)) — mineral

Rose Quartz Beads

SiO2 (Silicon Dioxide with trace inclusions of Ti, Fe, or Mn)

Quartzite River Rock (Metamorphic Quartzite (primarily SiO2)) — metamorphic

Quartzite River Rock

Metamorphic Quartzite (primarily SiO2)

Bixbyite on Rhyolite (Bixbyite (Mn2+,Fe3+)2O3) — mineral

Bixbyite on Rhyolite

Bixbyite (Mn2+,Fe3+)2O3

Citrine Quartz (Silicon Dioxide (SiO2)) — mineral

Citrine Quartz

Silicon Dioxide (SiO2)

Milky Quartz with Dendritic Inclusions (Silicon Dioxide (SiO2)) — mineral

Milky Quartz with Dendritic Inclusions

Silicon Dioxide (SiO2)

Septarian Nodule (Septarian Concretion (CaCO3 with Siderite and Calcite/Aragonite infusions)) — sedimentary

Septarian Nodule

Septarian Concretion (CaCO3 with Siderite and Calcite/Aragonite infusions)

Sunstone with Black Tourmaline (Arfvedsonite) (Feldspar (Na,Ca)(Al,Si)4O8 with Schorl Na(Fe3+)3Al6(Si6O18)(BO3)3(OH)3(OH)) — mineral

Sunstone with Black Tourmaline (Arfvedsonite)

Feldspar (Na,Ca)(Al,Si)4O8 with Schorl Na(Fe3+)3Al6(Si6O18)(BO3)3(OH)3(OH)

Cuprite (Cuprite (Copper(I) oxide, Cu2O)) — mineral

Cuprite

Cuprite (Copper(I) oxide, Cu2O)

Malachite (Copper(II) carbonate hydroxide, Cu2CO3(OH)2) — mineral

Malachite

Copper(II) carbonate hydroxide, Cu2CO3(OH)2

Prehnite (Prehnite (Ca2Al(AlSi3O10)(OH)2)) — mineral

Prehnite

Prehnite (Ca2Al(AlSi3O10)(OH)2)

Desert Rose (Gypsum (CaSO4·2H2O) or Barite (BaSO4) with Sand inclusions) — mineral

Desert Rose

Gypsum (CaSO4·2H2O) or Barite (BaSO4) with Sand inclusions

Red Jasper (Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)) — sedimentary

Red Jasper

Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)

Basalt (Basalt (High-iron/magnesium silicate rock)) — igneous

Basalt

Basalt (High-iron/magnesium silicate rock)

Peach Moonstone (Orthoclase Feldspar (KAlSi3O8)) — mineral

Peach Moonstone

Orthoclase Feldspar (KAlSi3O8)