Opaline Glass (Opalite)
Synthetic Silicon Dioxide Glass
Mineraloid (Man-made)
Category
Amorphous Solid
Browse amorphous solid specimens identified by the Rock Identifier community.
Opal (Precious Opal)
Hydrated Silica (SiO2·nH2O)
mineral
Fire Opal (in matrix)
Hydrated Silica (SiO2·nH2O)
Mineraloid
Moqui Marble (Ironstone Concretion)
Iron Oxide Concretion (Fe2O3 / FeO(OH))
sedimentary
Obsidian
Volcanic Glass (SiO2)
igneous
Scoria (Volcanic Rock)
Scoria (often basaltic scoria)
Igneous
Obsidian
Volcanic Glass (70-75% SiO2)
igneous
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
igneous
Naga Silver-Inlaid Ebony and Bone/Horn Beads
Diospyros (Ebony) or Keratin (Horn) with Silver/White-Metal Inlay
Organic (Anthropological Artifact)
Obsidian
Volcanic Glass (Primary component: SiO2)
igneous
Moqui Marble (Shaman Stone)
Ironstone Concretion (Fe2O3) - primarily Hematite or Goethite shell with Sandstone core
sedimentary
Man-made Slag (Industrial Byproduct)
Anthropogenic Glassy Residue
not a natural rock
Amber
Succinite (with approximate formula C10H16O)
mineraloid
Obsidian Arrowhead
Volcanic Glass (70% or more SiO2)
Igneous
Gossan with Copper Carbonate (Chrysocolla/Malachite)
Ferruginous Oxide (Gossan) with Cu2CO3(OH)2 (Malachite) or (Cu,Al)2H2Si2O5(OH)4 (Chrysocolla)
Mineral/Sedimentary Interface
Amber
Succinite (a Fossilized Tree Resin); Chemical formula is approximately C10H16O
Organic mineraloid
Iron Slag
Anthropogenic pyrometallurgical residue
industrial byproduct
Amber / Copal
Succinite (fossilized resin)
mineraloid
Mahogany Obsidian
Obsidian (volcanic glass with Hematite/Magnetite inclusions)
igneous
Anthracite Coal
Anthracite (Carbon Content: 86%–98%)
metamorphic
Anthracite Coal
Low-grade metamorphic carbonaceous rock
metamorphic
Amber
Succinite
mineraloid
Ferro-Manganese Slag
Vitreous Silicate Slag
Anthropogenic (Industrial byproduct)
Bituminous Coal
Organic Sedimentary Rock (Carbon-based)
sedimentary
Opalite
Synthetically produced glass (Silicon Dioxide with metallic inclusions)
Mineraloid (Man-made Glass)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurity)
Igneous
Obsidian
Obsidian (principally SiO2/Silicon dioxide)
igneous
Chrysocolla
Chrysocolla - (Cu,Al)2H2Si2O5(OH)4·nH2O
mineral
Opalite (Man-made Glass)
Synthetic Opalised Glass
mineral
Red Sandstone (Iron-rich Sandstone)
Clastic Sedimentary Rock - Quartz Arenite / Arkose with Hematite Cement
sedimentary
Mahogany Obsidian
Volcanic Glass (SiO2 + Fe2O3)
igneous
Mahogany Obsidian or Red Jasper
Silicon Dioxide with Iron Oxide (SiO2+Fe2O3)
Mineral/Igneous (Volcanic Glass)
Opalite
Synthetic Glass, SiO2 base with metallic inclusions
mineraloid (synthetic)
Black Obsidian
Volcanic Glass (SiO2 + impurities)
igneous
Amber
Succinite (Fossilized Resin C10H16O)
Organic Mineraloid
Obsidian
Volcanic Glass (SiO2)
igneous
Coquina / Limonite-stained Limestone
Sedimentary Limestone with Iron Oxyhydroxide (FeO(OH)·nH2O)
sedimentary
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurity isotopes)
igneous
Petrified Wood
Silicified Wood (SiO2)
mineral
Moqui Marble (Shaman Stone)
Iron Oxide Concretion (Hematite/Goethite shell with Sandstone core)
sedimentary
Amber
Succinite (specifically for Baltic amber); C10H16O (Variable organic compound)
mineral
Limonite (Iron Ore)
Limonite (Hydrous ferric oxides), generic formula FeO(OH)·nH2O
mineral