Red Slag Glass
Amorphous Silica (Industrial byproduct with metallic oxide dopants)
Mineraloid / Industrial Byproduct
Category
Amorphous Solid
Browse amorphous solid specimens identified by the Rock Identifier community.
Learn about Amorphous Solid in the encyclopedia
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Cullet Glass (Slag)
Amorphous Silicon Dioxide (Man-made)
Mineraloid
Tektite
Tektite (Amorphous silica rich glass)
mineral
Mexican Cantera Opal
Amorphous hydrated silica (SiO2·nH2O) in Rhyolitic host rock
gemstone
Cullet Glass (sometimes mistaken for Blue Obsidian or Slag)
Amorphous Silicon Dioxide (SiO2) with chemical additives (e.g., Cobalt for blue color)
mineraloid / industrial byproduct
Fire Opal
Hydrated amorphous silica (SiO2·nH2O)
gemstone
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
igneous
Pink Opal
Hydrated amorphous silica (SiO2·nH2O)
gemstone
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
igneous
Obsidian
Volcanic glass (Amorphous silicon dioxide)
igneous
Black Opal
Amorphous Hydrated Silica (SiO2·nH2O)
mineral
Amber
Fossilized Tree Resin (Amorphous Hydrocarbon)
Mineral
Moldavite
Tektite (Amorphous Silica, SiO2 + Al2O3)
mineral
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Mineral
Pink Opal
Hydrated Amorphous Silica (SiO2·nH2O)
mineraloid
Cullet Glass (Man-made Glass Slag)
Amorphous Silica (SiO2) with chemical additives
Mineraloid
Goldstone (with Tiger's Eye and Quartz)
Aventurine glass (Synthetic SiO2 with Cu inclusions)
mineral
Black Opal
Hydrated Amorphous Silica (SiO2 "n" H2O)
gemstone
Obsidian
Obsidian (Amorphous volcanic glass, SiO2 with impurities)
igneous
Eyestone Flint
SiO2 (Microcrystalline Quartz / Flint)
sedimentary
Limonite Ironstone
Goethite-Limonite concretion / Iron oxide
sedimentary
Generic Pebble
Lithic Fragment
sedimentary
Black Obsidian
Volcanic glass
igneous
Amber
Fossilized Tree Resin
gemstone
Pyrite Nodule
Iron Sulfide (FeS2)
mineral
Fossil Shark Tooth
Chondrichthyes tooth fossil
fossil
Waterworn Pebble / Quartzite
Metamorphic/Sedimentary rock fragment
sedimentary
Opalite
Synthetic glass / Opalized glass
gemstone
Leopardite
Quartz porphyry / Quartz monzonite with manganese oxide spots
igneous
Obsidian
Volcanic Glass
igneous
Worn River Pebble with Fossil Indentation
Sedimentary Rock with Fossil Infill
sedimentary
Fossilized Shell
Invertebrate fossil (Bivalvia or Brachiopoda)
fossil
Fossilized Shark Tooth
Chondrichthyes (Class) - likely Carcharodon or Otodus genus
fossil
Limonite / Ironstone
Hydrated Iron Oxide (FeO(OH)·nH2O)
sedimentary
Amber
Fossilized Tree Resin (Succinite for Baltic varieties)
fossil
Gold Sheen Obsidian
Volcanic Glass (SiO2 with inclusions)
igneous
Limonite on Sandstone
Iron Oxyhydroxide (FeO(OH)·nH2O) on Quartz Sandstone
sedimentary
Slag
Anthropogenic Vitreous Silicate / Ferro-silicate Slag
igneous
Snowflake Obsidian
Volcanic Glass with Spherulite inclusions (mainly Cristobalite)
igneous
Limonite Concretion
Hydrated Iron(III) Oxide-Hydroxide (FeO(OH)wnH2O)
sedimentary
Black Obsidian
Extrusive Volcanic Glass (primarily SiO2)
igneous
Limitation Concretion
Ironstone Concretion (Goethite/Limonite)
sedimentary