Rock Identifier

Category

Organic (Often Found By Beachcombers)

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

Schist (Graphite or Mica rich) (Crystalline Schist (often containing Muscovite, Biotite, or Graphite)) — metamorphic

Schist (Graphite or Mica rich)

Crystalline Schist (often containing Muscovite, Biotite, or Graphite)

Green Aventurine (Silicon Dioxide (SiO2) with Fuchsite inclusions) — metamorphic

Green Aventurine

Silicon Dioxide (SiO2) with Fuchsite inclusions

Limonite (Limonite (Hydrated iron oxide mixture, FeO(OH)·nH2O)) — mineral

Limonite

Limonite (Hydrated iron oxide mixture, FeO(OH)·nH2O)

Granodiorite (Granodiorite (containing Plagioclase, Quartz, and Biotite)) — igneous

Granodiorite

Granodiorite (containing Plagioclase, Quartz, and Biotite)

Sandstone (Clastic sedimentary rock (primarily SiO2)) — sedimentary

Sandstone

Clastic sedimentary rock (primarily SiO2)

Pumice (Pumice (Vitreous volcanic rock)) — igneous

Pumice

Pumice (Vitreous volcanic rock)

Fluorite (translucent octahedral crystal) (Calcium fluoride (CaF2)) — mineral

Fluorite (translucent octahedral crystal)

Calcium fluoride (CaF2)

Crushed Stone (Basalt/Gabbro) (Mafic Igneous Rock (primarily Plagioclase and Pyroxene)) — igneous

Crushed Stone (Basalt/Gabbro)

Mafic Igneous Rock (primarily Plagioclase and Pyroxene)

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

Quartz (Iron-stained)

Silicon Dioxide (SiO2)

Aquamarine (Beryllium aluminum silicate (Be3Al2Si6O18)) — mineral

Aquamarine

Beryllium aluminum silicate (Be3Al2Si6O18)

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

Quartzite Pebble

Metamorphic Quartzite (primarily SiO2)

Banded Agate (Microcrystalline Quartz (SiO2) with impurities) — mineral

Banded Agate

Microcrystalline Quartz (SiO2) with impurities

Milky Quartz (Silicon Dioxide (SiO2)) — mineral

Milky Quartz

Silicon Dioxide (SiO2)

Blue Quartzite (Quartzite with inclusions (often Dumortierite or Magnesio-riebeckite)) — metamorphic

Blue Quartzite

Quartzite with inclusions (often Dumortierite or Magnesio-riebeckite)

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

Citrine Quartz

Citrine (Silicon Dioxide, SiO2)

Gold Nugget (Native Gold (Au)) — mineral

Gold Nugget

Native Gold (Au)

Chert (Flint) (Chert (microcrystalline quartz)) — sedimentary

Chert (Flint)

Chert (microcrystalline quartz)

Gold Ore in Matrix (Native Gold (Au) in Quartz/Limonite host rock) — mineral

Gold Ore in Matrix

Native Gold (Au) in Quartz/Limonite host rock

Diorite (Phaneritic Intermediate Igneous Rock) — igneous

Diorite

Phaneritic Intermediate Igneous Rock

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

Chert (Yellow Jasper)

Microcrystalline Quartz (SiO2)

Granite (Granite (Phaneritic intrusive igneous rock; primarily SiO2 and Al2O3)) — igneous

Granite

Granite (Phaneritic intrusive igneous rock; primarily SiO2 and Al2O3)

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

Banded Chert

Silicon Dioxide (SiO2) - Microcrystalline Quartz

Chert (with Iron Staining) (Microcrystalline or Cryptocrystalline Quartz (SiO2)) — sedimentary

Chert (with Iron Staining)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Herkimer Diamond (Quartz (Silicon Dioxide) - SiO2) — mineral

Herkimer Diamond

Quartz (Silicon Dioxide) - SiO2

Quartz (Silicon dioxide (SiO2)) — Mineral

Quartz

Silicon dioxide (SiO2)

Granite (Phaneritic Felsic Igneous Rock) — igneous

Granite

Phaneritic Felsic Igneous Rock

Chert (Jasper variation) (Silicon Dioxide (SiO2)) — sedimentary

Chert (Jasper variation)

Silicon Dioxide (SiO2)

Jade (Nephrite and Jadeite) (Nephrite: Ca2(Mg,Fe)5Si8O22(OH)2; Jadeite: NaAlSi2O6) — metamorphic

Jade (Nephrite and Jadeite)

Nephrite: Ca2(Mg,Fe)5Si8O22(OH)2; Jadeite: NaAlSi2O6

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

Sodalite

Sodium Aluminum Silicate Chloride (Na8(Al6Si6O24)Cl2)

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

Rhodonite

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

Chert (Chert (SiO2)) — sedimentary

Chert

Chert (SiO2)

Rhodonite (Rhodonite (Manganese Silicate), chemical formula: (Mn,Fe,Mg,Ca)SiO3) — Mineral

Rhodonite

Rhodonite (Manganese Silicate), chemical formula: (Mn,Fe,Mg,Ca)SiO3

Fluorite (Calcium Fluoride (CaF2)) — mineral

Fluorite

Calcium Fluoride (CaF2)

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

Lepidolite

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

Carnelian (Carnelian (Silicon Dioxide: SiO2 with Iron Oxide impurities)) — mineral

Carnelian

Carnelian (Silicon Dioxide: SiO2 with Iron Oxide impurities)

Malachite (Malachite (Cu2CO3(OH)2)) — mineral

Malachite

Malachite (Cu2CO3(OH)2)

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

Chert (Flint)

Chert (Microcrystalline Quartz, SiO2)

Emerald with Matrix (Emerald in Mica Schist) (Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities) — mineral

Emerald with Matrix (Emerald in Mica Schist)

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Greywacke (River Pebble) (Greywacke (Indurated Sandstone)) — sedimentary

Greywacke (River Pebble)

Greywacke (Indurated Sandstone)

Rose Quartz (Rose Quartz (SiO2)) — mineral

Rose Quartz

Rose Quartz (SiO2)

Granite (Granite (Felsic Plutonic Rock)) — igneous

Granite

Granite (Felsic Plutonic Rock)

Jadeite Jade (NaAlSi2O6 (Sodium Aluminum Silicate)) — metamorphic

Jadeite Jade

NaAlSi2O6 (Sodium Aluminum Silicate)