Sandstone Chert/Quartzite
Silicon Dioxide (SiO2) - Sedimentary Sandstone / Orthoquartzite
sedimentary
Category
Amorphous Solid
Browse amorphous solid specimens identified by the Rock Identifier community.
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Porphyritic Basalt (Chinese Writing Stone/Flower Stone)
Porphyritic Basalt (primarily Plagioclase Feldspar in a Mafic groundmass)
igneous
Obsidian
Obsidian (volcanic glass), predominantly Silicon Dioxide (SiO2)
igneous
Pumice
Pumice (Vesicular volcanic glass)
igneous
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
igneous
Obsidian
Volcanic Glass (predominantly SiO2)
igneous
Indochinite Tektite
Tektite (high-silica impact glass)
igneous
Limonite Concretion
Goethite/Limonite concretion (FeO(OH)·nH2O)
sedimentary
Pumice
Pumice (Volcanic Rock / Glass Froth)
igneous
Pumice
Pumice (Volcanic Rock)
igneous
Septarian Nodule (Brown)
Septarian Concretion (Calcite, Aragonite, Limestone, and Barite)
sedimentary
Chrysocolla
Hydrated copper phyllosilicate, (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Chrysanthemum Stone
Limestone with Celestine or Andalusite inclusions
sedimentary
Petrified Wood
Silicified wood (Quartz, SiO2)
fossil
Petrified Wood
Silicified Wood (SiO2)
fossil
Amber
Fossilized Tree Resin
gemstone
Pumice
Pumice (volcanic glass foam)
igneous
Quartz-veined Metamorphic Pebble
Silicate-rich metamorphic rock with quartz veins (SiO2)
metamorphic
Fulgurite
Fulgurite (Lechatelierite or fused sand/quartz)
mineral
Wishing Stone / Banded Quartz Vein Pebble
Sedimentary pebble with hydrothermal quartz veins (SiO2)
sedimentary
Cannonball Concretion
Calcite-cemented Sandstone Concretion
sedimentary
Coal
Bituminous Coal / Anthracite
sedimentary
Sandstone
Clastic Sedimentary Rock
sedimentary
Jasper
Microcrystalline quartz (SiO2)
sedimentary
Pumice or Scoriaceous Basalt
Vesicular volcanic rock
igneous
Amber
Succinite (Fossilized Tree Resin)
fossil
Amber
Succinite (fossilized tree resin, C10H16O)
fossil
Slag Glass
SiO2 (Silicon Dioxide) with impurities
man-made glass
Pumice
Pumice (Vesicular Rhyolite/Andesite)
igneous
Tektite (Indochinite)
Tektite (High-silica natural glass)
mineralogical glass/meteorite impactite
Slag (Industrial Byproduct)
Ferro-silicate glass (Slag)
Anthropogenic (Man-made industrial deposit)
Sandstone Concretion
Moqui Marble / Ironstone Concretion (Iron oxide-cemented sandstone)
sedimentary
Amber
Succinite (Resin C10H16O)
mineral
Laterite
Laterite (Ferricrete)
sedimentary
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Igneous
Obsidian (specifically Silver Sheen Obsidian)
Volcanic Glass (approx. 70–75% SiO2 plus MgO, Fe3O4)
igneous
Industrial Slag
Anthropogenic Vitreous Slag
igneous
Precious Opal in Matrix
Hydrated Silica (SiO2·nH2O)
mineral
Iron Slag
Anthropogenic Vitreous Ferrous Silicate
industrial byproduct (anthropogenic)
Ironstone Concretion / Limonite-stained Siltstone
Ironstone (primarily Limonite FeO(OH)·nH2O and Siltstone)
sedimentary
Jet
Lignite (Anthracite-grade compact coal)
sedimentary
Ferruginous Slag (Iron Smelting Byproduct)
Anthropogenic Vitreous Silicate (often containing Fayalite: Fe2SiO4)
Mineraloid/Anthropogenic (Technofossil)