Limonite
FeO(OH)·nH2O
mineral
Category
Amorphous Solid
Browse amorphous solid specimens identified by the Rock Identifier community.
Learn about Amorphous Solid in the encyclopedia
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Pumice
Pumice (Volcanic Rock / Glass Froth)
igneous
Petrified Wood
Silicified Wood (SiO2)
fossil
Limonite Nodules / Goethite
Hydrated Iron Oxide-Hydroxide (FeO(OH)·nH2O / Fe2O3·nH2O)
mineral
Petrified Wood
Silicified Wood / Xylopal (SiO2)
fossil
Septarian Nodule Slice
Calcite-bearing Septarian Concretion
sedimentary
Pearl (with Peridot)
Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4
mineral
Slate
Slate (a fine-grained, foliated metamorphic rock). Mineral composition: Primarily composed of mica minerals (muscovite, chlorite, sericite) and quartz, with minor amounts of hematite, pyrite, and other accessory minerals.
sedimentary
Yellow Quartz Pebble
Quartz (Silicon Dioxide - SiO2)
mineral
Limonite (after Pyrite Pseudomorph)
Limonite (Hydrated Iron Oxide Mixture, FeO(OH)·nH2O)
mineral
Conglomerate (Asphaltic/Anthropogenic)
Clastic sedimentary rock / Bituminous mixture
sedimentary
Obsidian with Cristobalite
Volcanic Glass (Amorphous Silicon Dioxide) with Cristobalite inclusions
igneous
Pumice
Pumice (Amorphous silicate glass with trapped gas bubbles)
igneous
Pumice
Vesicular Rhyolite or Dacite Pumice (Amorphous volcanic glass)
igneous
Slag
Ferrous Slag (Amorphous calcium-magnesium-aluminum silicates)
igneous (artificial/anthropogenic)
Pumice
Pumicite (fine-grained pumice), Scoria (similar origin but denser and darker, usually basaltic)
Igneous
Obsidian
Volcanic Glass (felsic composition)
igneous
Kidney Stone (Urolith)
Calculus renalis (Biogenic mineral aggregate)
mineral
Pumice
Pumice (Vesicular Felsic Igneous Rock)
igneous
Ironstone Concretion (likely)
Goethite/Hematite/Limonite cemented sediment
Sedimentary Rock
Obsidian
Volcanic glass
igneous
Pumice
Vesicular volcanic glass (primarily SiO2 with Al2O3)
Igneous
Slag (Industrial By-product)
Glassy silicate or metallic smelting residue
mineral-like (anthropogenic)
Pumice
Vesicular Rhyolite or Dacite
igneous
Chrysocolla in Malachite
Cu2CO3(OH)2 (Malachite) / Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla)
mineral
Obsidian (black volcanic glass)
Obsidian; primarily amorphous SiO₂-rich rhyolitic glass
igneous
Pumice
Pumice (Vesicular Felsic Igneous Rock)
igneous
Petrified Wood
Silicified Wood (SiO2)
fossil
Smelter Slag
Anthropogenic Silicate Slag
igneous
Sandstone
Clastic Sedimentary Rock
sedimentary
Amber
Succinite / Fossilized Resin (C10H16O)
fossil
Precious Opal
Hydrated Silicon Dioxide (SiO2·nH2O)
gemstone
Polished black stone, likely black obsidian
Obsidian (volcanic glass), primarily silica-rich rhyolitic composition
igneous
Sandstone
Clastic Sedimentary Rock
sedimentary
Fossilized Shark Tooth
Chondrichthyes tooth
fossil
Slag (Industrial Glass/Metal Waste)
Artificial silicate/ferro-silicate byproduct
Mineraloid (Industrial byproduct)
Opalite (Man-made Glass)
Fused glass (typically made of dolomite and metal opacifiers)
Man-made Material / Glass
Fulgurite
Lechatelierite (vitreous silica / silica glass)
mineral
Shale
Clastic Sedimentary Rock
sedimentary
Pumice
Pumice (a volcanic glass, primarily SiO2 with Al2O3)
igneous
Synthetic Resin / Plastic Figurine
Synthetic Polymer (Copolymer of Polyethylene or Resin)
Mineraloid-like Synthetic Material
Orange Tabby (Felis catus)
Felis silvestris catus (variety: Red Mackerel Tabby)
Organic/Biological specimen (Non-Mineral)