Obsidian
Obsidian (Volcanic Glass)
Igneous
Category
Mineral Like Biological Tissue
Browse mineral like biological tissue specimens identified by the Rock Identifier community.
Learn about Mineral Like Biological Tissue in the encyclopedia
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Iron-stained Quartz (Gossan/Limonite-coated Quartz)
Silicon Dioxide (SiO2) with Hydrated Iron Oxides (FeO(OH)·nH2O)
mineral
Ferruginous Quartz (Red Quartz)
Silicon Dioxide with Iron Oxide inclusions (SiO2 + Fe2O3)
mineral
Fossil Sponge / Horn Coral / Crinoid Stem
Phylum Porifera or Cnidaria fossilized in calcium carbonate / silica
fossil
Jasper
Jasper (Silicon Dioxide, SiO2)
sedimentary
Ironstone Concretion
Siderite or Limonite Concretion
sedimentary
Blue Quartzite
Quartzite (silicon dioxide, SiO2)
metamorphic
Limonite (Iron Ore)
Limonite (Hydrous ferric oxides), generic formula FeO(OH)·nH2O
mineral
Green Jasper
Silicon Dioxide (SiO2) with impurities
sedimentary
Chalcanthite (Likely Synthetic/Lab-Grown)
Hydrated copper(II) sulfate (CuSO4·5H2O)
mineral
Chalcedony Geode (Botryoidal Agate)
Silicon Dioxide (SiO2)
mineral
Green Fluorite
Calcium Fluoride (CaF2)
mineral
Yellow Calcite
Calcium Carbonate (CaCO3)
mineral
Copper Ore
Cupriferous Rock / Mixed Mineral Matrix
igneous
Quartz (likely Chalcedony or Chert)
Silicon Dioxide (SiO2)
mineral
Sandstone
Arenite (composed primarily of SiO2)
sedimentary
Red Sandstone
Arenite (Ferruginous Sandstone)
sedimentary
Snowflake Obsidian
Obsidian with Cristobalite inclusions (SiO2)
igneous
Magnetite
Magnetite (Fe3O4)
mineral
Fossil Shark Tooth
Odontaspididae (Sand Tiger Shark family)
fossil
Granite
Intrusive igneous felsic rock
igneous
Granite
Phaneritic Plutonic Felsic Rock
igneous
Garnet (Almandine)
Almandine (Fe3Al2(SiO4)3)
mineral
Quartz (specifically Milky or Clear Quartz)
Silicon Dioxide (SiO2)
mineral
Quartz / Milky Quartz
Silicon Dioxide (SiO2)
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Obsidian
Obsidian (Volcanic Glass, SiO2)
igneous
Quartz Vein (Iron-stained)
Silicon Dioxide (SiO2) with limonite/hematite staining
mineral
Vesicular Basalt
Basalt with vesicular texture
igneous
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
mineral
Agatized Dinosaur Bone
Permineralized Dinosaur Bone (Silicified/Agatized Bone)
fossil
Mica Schist
Mica Schist (varies based on mineral makeup, often Biotite/Muscovite schist)
metamorphic
Fossilized Fish (Lepidotes)
Lepidotes sp. (Order: Lepisosteiformes)
sedimentary
Obsidian (Gold Sheen)
Obsidian (SiO2 + impurities)
igneous
Turquoise
Turquoise (CuAl6(PO4)4(OH)8·4H2O)
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Fuchsite
K(Al,Cr)2(AlSi3O10)(OH)2 (Chromium-rich Muscovite)
mineral
Chalcedony
Cryptocrystalline Quartz (SiO2)
mineral
Smoky Quartz with Axinite
SiO2 (Quartz) with (Ca,Mn,Fe,Mg)3Al2BSi4O15(OH) (Axinite)
mineral
Quartz (Clear Quartz)
Silicon Dioxide (SiO2)
mineral
Quartz Geode
Silicon Dioxide (SiO2) - Crystalline Quartz
mineral