Rock Identifier

Category

Organic (Geological Relative)

Browse organic (geological relative) specimens identified by the Rock Identifier community.

Sodalite (Na8(Al6Si6O24)Cl2 (Sodalite)) — mineral

Sodalite

Na8(Al6Si6O24)Cl2 (Sodalite)

Stichtite in Serpentine (Atlantisite) (Mg6Cr2CO3(OH)16·4H2O (Stichtite) within Mg3Si2O5(OH)4 (Serpentine)) — Metamorphic

Stichtite in Serpentine (Atlantisite)

Mg6Cr2CO3(OH)16·4H2O (Stichtite) within Mg3Si2O5(OH)4 (Serpentine)

Red Scoria (Lava Rock) (Scoria (Vesicular Basalt/Andesite)) — igneous

Red Scoria (Lava Rock)

Scoria (Vesicular Basalt/Andesite)

Vesicular volcanic scoria (likely basaltic scoria) (Scoria; predominantly iron- and magnesium-rich silicate glass with plagioclase, pyroxene, and possible olivine) — igneous

Vesicular volcanic scoria (likely basaltic scoria)

Scoria; predominantly iron- and magnesium-rich silicate glass with plagioclase, pyroxene, and possible olivine

Weathered iron-rich concretion or laterite fragment (Ferruginous concretion, likely goethite/limonite (hydrated iron oxides) in a clay-rich matrix) — sedimentary

Weathered iron-rich concretion or laterite fragment

Ferruginous concretion, likely goethite/limonite (hydrated iron oxides) in a clay-rich matrix

Blue Calcite (Calcium Carbonate (CaCO3)) — mineral

Blue Calcite

Calcium Carbonate (CaCO3)

Blue magnesite beads (Magnesite (MgCO₃), likely stabilized or dyed; brown veining may reflect matrix or iron oxides) — mineral

Blue magnesite beads

Magnesite (MgCO₃), likely stabilized or dyed; brown veining may reflect matrix or iron oxides

Weathered basaltic volcanic rock (Likely vesicular basalt or basaltic-andesite; chiefly plagioclase, pyroxene, and iron-bearing minerals) — igneous

Weathered basaltic volcanic rock

Likely vesicular basalt or basaltic-andesite; chiefly plagioclase, pyroxene, and iron-bearing minerals

Tumbled green gemstone, likely dyed howlite or serpentine (Most consistent with dyed howlite (Ca2B5SiO9(OH)5); exact identification requires testing) — mineral

Tumbled green gemstone, likely dyed howlite or serpentine

Most consistent with dyed howlite (Ca2B5SiO9(OH)5); exact identification requires testing

Calcite (or Alabaster, if truly carved) (Calcium Carbonate (CaCO3)) — Mineral/Rock

Calcite (or Alabaster, if truly carved)

Calcium Carbonate (CaCO3)

Light-colored limestone (probable fossiliferous or micritic limestone) (Calcite-rich carbonate rock; predominantly CaCO₃ (calcite)) — sedimentary

Light-colored limestone (probable fossiliferous or micritic limestone)

Calcite-rich carbonate rock; predominantly CaCO₃ (calcite)

Tumbled sodalite (Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂) — mineral

Tumbled sodalite

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂

Tumbled sodalite beads (Sodalite, Na8(Al6Si6O24)Cl2, commonly with minor white calcite or nepheline) — mineral

Tumbled sodalite beads

Sodalite, Na8(Al6Si6O24)Cl2, commonly with minor white calcite or nepheline

Sodalite beads (Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂) — mineral

Sodalite beads

Sodalite, Na₈(Al₆Si₆O₂₄)Cl₂

Fluorite (Calcium Fluoride (CaF2)) — mineral

Fluorite

Calcium Fluoride (CaF2)

Likely weathered iron-rich rock (Probable basalt or limonite/goethite-stained mafic rock; exact identification requires testing) — igneous

Likely weathered iron-rich rock

Probable basalt or limonite/goethite-stained mafic rock; exact identification requires testing

Possible basalt or weathered mafic rock (Basalt; chiefly plagioclase feldspar and pyroxene, commonly with olivine and iron oxides) — igneous

Possible basalt or weathered mafic rock

Basalt; chiefly plagioclase feldspar and pyroxene, commonly with olivine and iron oxides

Iron-rich weathered rock or limonite/goethite nodule (Limonite (mixture dominated by goethite, FeO(OH)·nH₂O), possibly with quartz or clay) — mineral

Iron-rich weathered rock or limonite/goethite nodule

Limonite (mixture dominated by goethite, FeO(OH)·nH₂O), possibly with quartz or clay

Lava Rock (Scoria) (Scoria (Vesicular Basalt)) — igneous

Lava Rock (Scoria)

Scoria (Vesicular Basalt)

Weathered iron-rich concretion (probable limonite/goethite) (Limonite–goethite aggregate, approximately FeO(OH)·nH₂O) — mineral

Weathered iron-rich concretion (probable limonite/goethite)

Limonite–goethite aggregate, approximately FeO(OH)·nH₂O

Fluorite Octahedron (Fluorite (Calcium Fluoride, CaF2)) — mineral

Fluorite Octahedron

Fluorite (Calcium Fluoride, CaF2)

Malachite (Copper Carbonate Hydroxide [Cu2CO3(OH)2]) — mineral

Malachite

Copper Carbonate Hydroxide [Cu2CO3(OH)2]

Coquina (Biogenic Limestone) — sedimentary

Coquina

Biogenic Limestone

Goniatite Fossil (Goniatitida (Order), fossilized in limestone/calcite (CaCO3)) — sedimentary

Goniatite Fossil

Goniatitida (Order), fossilized in limestone/calcite (CaCO3)

Serpentinite (Serpentinite (composed primarily of minerals in the serpentine group: (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4)) — metamorphic

Serpentinite

Serpentinite (composed primarily of minerals in the serpentine group: (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4)

Fluorite (Calcium Fluoride (CaF2)) — mineral

Fluorite

Calcium Fluoride (CaF2)

Scoria (Vesicular Basalt / Scoriaceous Basalt) — igneous

Scoria

Vesicular Basalt / Scoriaceous Basalt

Weathered gray sandstone or siltstone (Clastic siliciclastic rock, primarily quartz and feldspar grains cemented by silica or carbonate) — sedimentary

Weathered gray sandstone or siltstone

Clastic siliciclastic rock, primarily quartz and feldspar grains cemented by silica or carbonate

Greenstone / Greenschist (Greenschist (metamorphosed mafic rock)) — metamorphic

Greenstone / Greenschist

Greenschist (metamorphosed mafic rock)

Blue-green fluorite (probable) (Fluorite, calcium fluoride (CaF₂)) — mineral

Blue-green fluorite (probable)

Fluorite, calcium fluoride (CaF₂)

Sandstone (Ferruginous) (Arenite (Iron-rich)) — sedimentary

Sandstone (Ferruginous)

Arenite (Iron-rich)

Green aventurine (likely) (Quartz variety; silicon dioxide (SiO₂) with green fuchsite mica inclusions) — mineral

Green aventurine (likely)

Quartz variety; silicon dioxide (SiO₂) with green fuchsite mica inclusions

Ironstone Concretion (Limonite/Goethite) (Ferruginous Sandstone / Ironstone (FeO(OH)·nH2O)) — sedimentary

Ironstone Concretion (Limonite/Goethite)

Ferruginous Sandstone / Ironstone (FeO(OH)·nH2O)

Colorless faceted gemstone, likely cubic zirconia (Cubic zirconia (synthetic zirconium dioxide, ZrO₂); possibly colorless quartz or laboratory diamond) — gemstone

Colorless faceted gemstone, likely cubic zirconia

Cubic zirconia (synthetic zirconium dioxide, ZrO₂); possibly colorless quartz or laboratory diamond

Sandstone with trace fossil (Sandstone, possibly with Skolithos or similar trace fossil) — sedimentary

Sandstone with trace fossil

Sandstone, possibly with Skolithos or similar trace fossil

Magnetite / Iron-Rich Concretion (Magnetite (Fe3O4) or Bog Iron Limonite) — mineral

Magnetite / Iron-Rich Concretion

Magnetite (Fe3O4) or Bog Iron Limonite

Micaceous schist (probable) (Mica schist, dominated by muscovite/biotite with quartz and feldspar) — metamorphic

Micaceous schist (probable)

Mica schist, dominated by muscovite/biotite with quartz and feldspar

Green Fluorite (Fluorite (Calcium Fluoride, CaF2)) — mineral

Green Fluorite

Fluorite (Calcium Fluoride, CaF2)

Scoria (Vesicular Basalt) (Scoria (Extrusive Igneous Rock)) — igneous

Scoria (Vesicular Basalt)

Scoria (Extrusive Igneous Rock)

Green Fluorite (Calcium Fluoride (CaF2)) — mineral

Green Fluorite

Calcium Fluoride (CaF2)

Granite (Granite (Phaneritic intrusive igneous rock)) — igneous

Granite

Granite (Phaneritic intrusive igneous rock)

Anthracite Coal (Anthracite (Carbon-based organic sedimentary rock exposed to metamorphic heat/pressure; Chemical composition is approximately 86%–98% Carbon)) — metamorphic

Anthracite Coal

Anthracite (Carbon-based organic sedimentary rock exposed to metamorphic heat/pressure; Chemical composition is approximately 86%–98% Carbon)