Sea Glass (Frosted Glass)
Amorphous Silica (SiO2) with various additives
Man-made material (Anthropogenic 'mineraloid')
Category
Amorphous Solid
Browse amorphous solid specimens identified by the Rock Identifier community.
Green Slag Glass
Amorphous Silicon Dioxide (with metallic impurities)
Igneous (Anthropogenic)
Obsidian (Apache Tear)
Amorphous Volcanic Glass (SiO2 + impurities)
igneous
Faceted Glass (Costume Jewelry)
Amorphous Silicon Dioxide with colorants (Glass)
Synthetic/Man-made Material
Green Slag Glass (Cullet)
Amorphous Silica (Industrial Glass Byproduct)
Synthetic/Byproduct (Non-igneous, non-sedimentary, non-metamorphic)
Anthracite Coal
Anthracite (Carbon-based organic sedimentary/metamorphic rock)
metamorphic
Goldstone (with Tiger's Eye and Quartz)
Aventurine glass (Synthetic SiO2 with Cu inclusions)
mineral
Obsidian
Obsidian (Amorphous volcanic glass, SiO2 with impurities)
igneous
Anthracite Coal
Anthracite
metamorphic
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
Man-made Glass (Tumbled/Shaped)
Amorphous Silicon Dioxide (SiO2) with metal oxide colorants
Mineraloid (synthetic)
Slag Glass (Cullet)
Amorphous Silicon Dioxide (SiO2) with metal oxide colorants
Anthropogenic (Man-made)
Shungite
Carbonaceous rock (primarily amorphous carbon)
Mineraloid
Mahogany Obsidian Arrowhead
Volcanic Glass with Hematite/Magnetite inclusions (Amorphous Silicon Dioxide)
igneous
Limonite (Yellow Ochre)
Limonite (an amorphous mixture of hydrated iron oxides, primarily FeO(OH)·nH2O)
mineral
Obsidian
Volcanic Glass (SiO2)
igneous
Ironstone Concretion (Moqui Marble)
Iron-oxide Concretion (Hydrated ferric oxide, Fe2O3·nH2O)
sedimentary
Limonite with Hematite
Limonite (FeO(OH)·nH2O) and Hematite (Fe2O3)
mineral
Ironstone Concretion (Ironstone Gourd)
Limonite/Goethite Concretion (FeOO(H))
sedimentary
Amber
Succinite (fossilized resin)
mineral
Amber
Succinite (approximate formula C10H16O)
mineraloid
Shungite
Non-crystalline carbon (high-carbon metamorphic rock)
metamorphic
Chert (Nodule)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
sedimentary
Obsidian
Volcanic Glass (SiO2 rich)
igneous
Obsidian with Mahogany Phasing
Volcanic Glass (SiO2 + Fe2O3)
igneous
Chrysocolla
Hydrated copper phyllosilicate mineral (Cu,Al)2H2Si2O5(OH)4·n(H2O)
mineral
Pearl
Calcium carbonate (CaCO3) - mainly Aragonite with Conchiolin
mineraloid
Asphalt / Bituminous Aggregate
Bituminous mixture (Hydrocarbon-based sediment)
sedimentary
Limonite (Iron Ore)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
mineral
Amber (in Matrix/Shale)
Amber (Fossilized Tree Resin)
mineral
Anthracite Coal
Anthracite (Carbon-rich metamorphic coal)
metamorphic
Quartz Vein in Host Rock (Pebble)
Quartz (SiO2) with sandstone or siltstone matrix
metamorphic/igneous transition
Asphalt (Bituminous Concrete)
Bituminous mix containing aggregates and petroleum-based binder (CnH2n+2)
not a rock (anthropogenic material/technofossil)
Amber
Succinite (Fossilized Tree Resin)
Organic Mineraloid
Coal (Anthracite)
Anthracite Coal (C)
sedimentary
Limonite Concretion (Ironstone)
Limonite (FeO(OH)·nH2O) / Goethite
sedimentary
Limonite (Ironstone Concretion)
Limonite (Hydrous ferric oxide mixture, FeO(OH)·nH2O)
sedimentary
Bumblebee Jasper
Hydrothermal Volcanic Rock (Primarily Calcite with Orpiment - As2S3, Realgar, and Pyrite)
igneous
Build-A-Bear Plush (Non-Geological)
Polyester fibers (C10H8O4)n and Synthetic Polymers
Anthropogenic / Non-mineral
Shungite
Non-crystalline carbonoid (Shungite)
metamorphic
Limonite (Gozzany Iron)
Limonite (FeO(OH)·nH2O)
mineral
Snowflake Obsidian
Volcanic glass with Spherulite inclusions (SiO2)
igneous