Limonite Concretion
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Category
Browse mineral like biological tissue specimens identified by the Rock Identifier community.
Limonite Concretion
Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)
Geode (Unopened)
Silica-rich Concretion (primarily SiO2)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Quartz Geode (Smoky Quartz)
Silicon Dioxide (SiO2)
Orthoclase Feldspar
Potassium aluminum silicate (KAlSi3O8)
Granite
Phaneritic Felsic Igneous Rock
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Black Obsidian
Volcanic Glass (SiO2 + impurities)
Botryoidal Black Chalcedony Geode (Black Grape Agate)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Schist
Mica Schist
Beryllonite
Beryllonite (NaBePO4)
Dendritic Agate
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Schist (Kyanite Schist)
Kyanite-Mica Schist (primarily Al2SiO5, KAl2(AlSi3O10)(OH)2, and SiO2)
Basalt
Basalt (Aphanitic Mafic Igneous Rock)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Septarian Nodule (Dragon Stone)
Septarian concretion (CaCO3 with Aragonite and Calcite)
Biotite (Black Mica)
Biotite - K(Mg,Fe)3AlSi3O10(F,OH)2
Sandstone
Arenite (SiO2 primarily)
Ferruginous Sandstone (Red Sandstone)
Arenite with Hematite/Limonite cement
Erythrite
Erythrite (Cobalt Bloom) - Co3(AsO4)2·8H2O
Banded Gneiss
Gneiss (High-grade Regional Metamorphic Rock)
Acrylic or Resin (Synthetic Imitation)
Polymethyl Methacrylate (PMMA) or Polyepoxide
Chrysocolla
Chrysocolla (Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O)
Porphyritic Basalt (with Amygdales)
Amygdaloidal Porphyritic Basalt
Schist
Mica Schist
Moss Agate
Silicon Dioxide with inclusions (SiO2)
Granite
Granite (Felsic Plutonic Rock)
Gneiss (specifically a Granitic Gneiss)
Gneiss (typically composed of Quartz, Feldspar, and Mica/Amphiboles)
Sandstone (with Iron Staining)
Clastic sedimentary rock (primarily SiO2)
Quartz Geode Fragment
Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Turquoise and Hematite
CuAl6(PO4)4(OH)8·4H2O (Turquoise) and Fe2O3 (Hematite)
Basalt with Iron Oxidation
Mafic Igneous Basalt
Banded Agate (Chert/Chaldcedony)
Silicon Dioxide (SiO₂)
Mahogany Obsidian
Volcanic Glass with Hematite/Magnetite (SiO2 + Fe2O3)
Aquamarine on Feldspar Matrix
Beryl (Be3Al2Si6O18) with Potassium Feldspar (KAlSi3O8)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Biotite (Mica)
K(Mg,Fe)3AlSi3O10(OH,F)2
Pyrope Garnet
Magnesium aluminum silicate (Mg3Al2Si3O12)
Copper Ore (with Malachite and Azurite)
Hydroxide copper carbonate (Cu2CO3(OH)2 / Cu3(CO3)2(OH)2)
Glaucophane Schist (Blueschist)
Blueschist (Glaucophane-bearing schist)