Coal (likely Bituminous or Lignite)
Organic Sedimentary Rock (Carbonaceous)
sedimentary
Category
Amorphous Solid
Browse amorphous solid specimens identified by the Rock Identifier community.
Goldstone (Red)
Aventurine Glass (Cupriferous glass)
Synthetic Glass (Man-made)
White Opal (Common)
Hydrated Silica (SiO2·nH2O)
mineral
Bituminous Coal (with Anthracite or Vitrinite inclusion)
Organic-rich Sedimentary Rock (Carboniferous classification)
sedimentary
Coquina or Fossilized Shell Aggregate
Calcareous bioclastic sedimentary rock (CaCO3)
sedimentary
Slag
Ferrous Slag (Siliceous industrial waste)
Anthropogenic (Man-made industrial byproduct)
Anthracite
Anthracite Coal (C)
sedimentary
Baltic Amber (Butterscotch or Egg Yolk Variety)
Succinite (chemical formula: C10H16O)
Organic Gemstone (not a rock or mineral)
Obsidian
Volcanic glass (Mainly SiO2)
igneous
Amber
Succinite (C10H16O)
mineraloid
Amber / Copal
Fossilized Tree Resin (Succinate)
Mineraloid
Petrified Wood
Silicified Wood (SiO2)
sedimentary
Limonite with Iron Inclusions
Limonite (Hydrated Iron Oxide, FeO(OH)·nH2O)
sedimentary
Amber
Succinite (fossilized tree resin), C10H16O
Organic Gemstone
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
igneous
Apache Tear (Obsidian)
Hydrated volcanic glass (SiO2 with inclusions)
igneous
Manganese Oxide Crust on Limestone
Manganese Oxides (e.g., Pyrolusite MnO2 or Romanechite) on CaCO3
sedimentary
Amber
Fossilized Tree Resin (C10H16O)
mineral
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
sedimentary
Obsidian (Black Obsidian)
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
igneous
Red Amber (Burmite/Cherry Amber)
Succinite / Retinite (Organic Fossilized Resin, C10H16O)
Mineraloid (Organic)
Ambergris
Ambrein (C30H52O Derivative)
Organic (Zoogenic)
Mahogany Obsidian
Volcanic glass (SiO2 + Fe2O3)
igneous
Slag
Anthropogenic Iron Silicate Glass
mineral
Obsidian
Obsidian (principally SiO2)
igneous
Iron Slag
Anthropogenic Iron oxide/Silicate composite
Mineral-like byproduct (Technogenic)
Dinosaur Fossil (Skull)
Dinosauria fossilis (Petrified Hydroxyapatite / Calcium Carbonate)
sedimentary
Amber
Succinite (fossilized tree resin)
mineral
Mahogany Obsidian
Volcanic glass containing Hematite or Magnetite (SiO2 + Fe2O3)
igneous
Amber (Rough)
Amber (Fossilized Tree Resin, succinite)
mineral
Chrysocolla in Matrix
Hydrated copper phyllosilicate (Cu,Al)2H2Si2O5(OH)4' nH2O on Quartz/Feldspar matrix
mineral
Obsidian
Obsidian (Volcanic Glass)
igneous
Moqui Marble
Ironstone Concretion (Goethite/Hematite)
sedimentary
Concrete
Anthropogenic Sedimentary Conglomerate (Cement mixture: typically Ca2SiO4, Ca3SiO5, Ca3Al2O6)
sedimentary (artificial)
Opalite
Synthetic Glass (SiO2 + impurities)
mineral
Slag (Industrial Glass)
Artificial Vitreous Silicate
mineraloid (anthropogenic)
Amber
Succinite (organic fossilized resin)
mineraloid
Amber
Succinite (fossilized tree resin)
mineral
Shungite (Noble/Type II)
Non-crystalline carbon (Fullerene-bearing carbonaceous rock)
metamorphic
Pumice (Vesicular Rhyolite/Andesite)
Pumice (a highly vesicular volcanic glass/extrusive igneous rock)
igneous
Tiffany Stone
Bertrandite (with Fluorite, Opal, and Chalcedony), Be4Si2O7(OH)2
mineral
Chrysocolla on Limonite Matrix
Cu2-xAlx(H2-xSi2O5)(OH)4·nH2O (Chrysocolla) on FeO(OH)·nH2O (Limonite)
mineral