Limonite Pseudomorph after Pyrite
Limonite (Hydrous iron oxides, FeO(OH)·nH2O) replacing Pyrite (FeS2)
mineral
Category
None
Browse none specimens identified by the Rock Identifier community.
Chert (specifically Jasper or Brown Chert node)
Microcrystalline Quartz (SiO2)
sedimentary
Black Obsidian
Volcanic Glass (predominantly SiO2, Silicon Dioxide)
igneous
Magnetite (Lodestone)
Magnetite (Fe3O4)
mineral
Obsidian
Volcanic Glass (70-75% SiO2)
igneous
Dinosaur Fossil (Tyrannosaurus rex skull replica/specimen)
Tyrannosaurus rex (fossilized in permineralized sedimentary matrix)
sedimentary
Green Sea Glass
Amorphous Silica (man-made glass), SiO2 + additive metal oxides
mineraloid / anthropogenic (man-made origin)
Sandstone Concretion
Clastic sedimentary rock (primarily Quartz SiO2)
sedimentary
Obsidian
Volcanic Glass (SiO2 - Silicon Dioxide with impurities)
Igneous
Specular Hematite (Specularite)
Iron Oxide (Fe2O3)
mineral
Obsidian
Volcanic Glass (SiO2 rich)
igneous
Obsidian
Amorphous volcanic glass (SiO2)
igneous
Cullet (Slag Glass)
Amorphous Silica (SiO2) with various metal oxide colorants
mineraloid / anthropogenic
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
igneous
Blue Dyed Agate Geode
Chalcedony (cryptocrystalline Quartz), SiO2
mineral
Siltstone with Quartz Vein
Siltstone (primarily SiO2, Al2O3, Fe2O3)
sedimentary
Amber
Succinite (fossilized tree resin)
mineral
Obsidian
Amorphous Volcanic Glass (primarily SiO2)
igneous
Obsidian (Black Obsidian)
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
igneous
Obsidian
Volcanic Glass (SiO2 + minor impurities)
igneous
Chert (Jasper/Flint Pebble)
Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)
sedimentary
Baroque Pearl
Calcium Carbonate (Aragonite or Calcite) and Conchiolin
Organic Gemstone
Amethyst
Quartz variety; SiO2 (Silicon Dioxide)
Mineral
Slag
Anthropogenic glassy silicate
Mineral-like byproduct
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Igneous
Apache Tears (Obsidian)
Volcanic Glass (SiO2)
igneous
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
igneous
Coal (specifically Bituminous or Anthracite)
Organic sedimentary rock; primarily Carbon (C) with varying H, S, O, N
sedimentary
Cullet Glass (Strawberry Glass)
Amorphous Silicon Dioxide (SiO2) with metallic dopants
Mineraloid (Synthetic/Man-made)
Green Slag Glass (Cullet)
Amorphous Silica (Industrial Glass Byproduct)
Synthetic/Byproduct (Non-igneous, non-sedimentary, non-metamorphic)
Quartzite
Quartzite (primarily SiO2)
metamorphic
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
igneous
Obsidian
Volcanic Glass (SiO2 + impurities)
igneous
Obsidian
Obsidian (Volcanic Glass)
igneous
Hematite (Iron Ore)
Hematite (Fe2O3)
mineral
Anthracite Coal
Anthracite (high-rank coal / Carbon)
metamorphic
Obsidian
Obsidian (volcanic glass), predominantly Silicon Dioxide (SiO2)
igneous
Obsidian
Volcanic Glass (predominantly SiO2 – Silicon Dioxide, but non-crystalline)
Igneous
Rose Quartz
Rose Quartz (SiO2)
mineral
Conglomerate
Conglomerate (Detrital sedimentary rock)
sedimentary
Synthetic Costume Glove (Paws)
Polyethylene terephthalate (Polyester) & Polyurethane blend
Non-geological / Man-made textile
Conglomerate
Clastic Sedimentary Conglomerate (SiO2, CaCO3, etc.)
sedimentary