Coquina
Biogenic Limestone
sedimentary
Category
Organic (Geological Relative)
Browse organic (geological relative) specimens identified by the Rock Identifier community.
Ironstone Concretion (Limonite/Goethite)
Ferruginous Sandstone / Ironstone (FeO(OH)·nH2O)
sedimentary
Sandstone (Ferruginous)
Arenite (Iron-rich)
sedimentary
Scoria
Vesicular Basalt / Scoriaceous Basalt
igneous
Anthracite Coal
Anthracite (Carbon-based organic sedimentary rock exposed to metamorphic heat/pressure; Chemical composition is approximately 86%–98% Carbon)
metamorphic
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Magnetite / Iron-Rich Concretion
Magnetite (Fe3O4) or Bog Iron Limonite
mineral
Scoria (Vesicular Basalt)
Vesicular Basalt
igneous
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
mineral
Granite
Granite (Phaneritic intrusive igneous rock)
igneous
Chrome Diopside
Magnesium Calcium Silicate (MgCaSi2O6) containing Chromium impurities
mineral
Scoria (Vesicular Basalt)
Scoria (Extrusive Igneous Rock)
igneous
Arsenopyrite with Quartz
Arsenopyrite (FeAsS)
mineral
Flower Agate (Cherry Blossom Agate)
Chalcedony (SiO2) with Opaque Inclusions
mineral
Serpentine Schist with Quartz Vein
Serpentine Schist (a type of Metamorphic rock). The white band is likely Quartz (SiO2).
Metamorphic
Red Scoria (Lava Rock)
Vesicular Basalt / Scoria
igneous
Fluorite (Purple Fluorite in Matrix)
Fluorite (Calcium Fluoride, CaF2)
mineral
Rhodonite
Rhodonite (Manganese Iron Magnesium Calcium Silicate) - (Mn,Fe,Mg,Ca)SiO3
Mineral
Fluorite (Rainbow or Multi-colored Fluorite)
Fluorite (Calcium Fluoride - CaF2)
mineral
Psilomelane (Black Hematite/Manganese Ore)
Barium Manganese Oxide (Formula: BaMn9O18(OH)4)
mineral
Coquina
Biogenic Limestone (Calcium Carbonate, CaCO3)
sedimentary
Greenstone
Metabasalt / Chlorite Schist
metamorphic
Grooved Maun Ball (Maul/Hammerstone-like Concretion)
Calcareous/Ferruginous Concretion in Sandstone Matrix
sedimentary
Chrysocolla
Chrysocolla (Cu,Al)2H2Si2O5(OH)4·nH2O
Mineral
Anthracite Coal
Coal (predominantly carbon)
sedimentary
Chert (varietal Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
sedimentary
Ruby Fuchsite / Ruby in Fuchsite
Ruby (Al2O3 variety corundum) and Fuchsite (K(Al,Cr)2AlSi3O10(OH)2 - a chromium-rich variety of muscovite mica) in Quartz matrix
Mineral
Fordite
Anthropogenic paint-rock
mineraloid (human-made geological specimen)
Quartz (Milky or Clear Quartz fragment)
Silicon Dioxide (SiO2)
mineral
Jadeite Jade
NaAlSi2O6 (Sodium Aluminum Silicate)
metamorphic
Amethyst
Amethyst is a variety of Quartz (SiO₂)
Mineral
Zebra Jasper
Silicon dioxide (SiO2) with various impurities
Sedimentary
Moonstone
Orthoclase Feldspar (specifically showing adularescence)
Mineral
Apatite
Apatite group mineral (e.g., Fluorapatite - Ca5(PO4)3F, Chlorapatite - Ca5(PO4)3Cl, Hydroxylapatite - Ca5(PO4)3(OH))
mineral
Obsidian
Volcanic Glass (predominantly SiO2 – Silicon Dioxide, but non-crystalline)
Igneous
Biotite Mica
Biotite (K(Mg,Fe)3AlSi3O10(F,OH)2)
mineral
Mookaite Jasper
Siliceous (chert) sedimentary rock, a form of Jasper
Sedimentary
Rose Quartz
Rose Quartz (SiO₂)
mineral
Ocean Jasper
Silicon Dioxide (SiO2)
Mineral_variety_of_Chalcedony
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Igneous
Orange Calcite
Calcite (CaCO3)
Mineral
Labradorite (a variety of Feldspar)
Labradorite; (Na,Ca)(Al,Si)4O8 (a plagioclase feldspar)
igneous