River Siltstone / Mudstone Pebble
Siltstone (composed of mixed silicate and carbonate minerals)
sedimentary
Category
Non Geological
Browse non geological specimens identified by the Rock Identifier community.
Slag Glass
Vitreous Silicate Residue
industrial byproduct (anthropogenic rock)
Black Obsidian
Volcanic Glass (SiO2)
igneous
Metal Chain (Likely Steel or a Steel Alloy)
Steel (primarily iron and carbon); specific alloy unknown
Man-made Object (Metal/Alloy)
Obsidian
Volcanic Glass (SiO2 rich)
igneous
Black Obsidian
Volcanic Glass (SiO2)
igneous
Slag (Industrial Glass)
Artificial Vitreous Silicate
mineraloid (anthropogenic)
Snowflake Obsidian
Volcanic glass (SiO2) with Cristobalite (SiO2) inclusions
igneous
Obsidian
Obsidian (Volcanic Glass, complex silicate)
igneous
Asphalt (Aggregate)
Bituminous macadam / Concrete Aggregate
sedimentary
Gold Ore (in Quartz/Sulfide matrix)
Native Gold (Au) in Quartz (SiO2) and Pyrite (FeS2)
mineral
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide , SiO2)
igneous
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Quartzite with Garnet
Garnetiferous Quartzite (SiO2 + X3Y2(SiO4)3)
metamorphic
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
igneous
Cupronickel (on a 1981 Mexico 20 Pesos coin)
Copper-Nickel Alloy (Cu75Ni25)
mineral
Obsidian
Volcanic Glass (SiO2 dominant)
igneous
Granite
Granite (Felsic Plutonic Rock)
igneous
Synthetic Resin Charm (Seal Shape)
Polymer Resin with plastic glitter / Polyethylene terephthalate glitters
Synthetic material (Not a rock or mineral)
Obsidian
Amorphous volcanic glass (70-75% SiO2)
igneous
Glass Nugget (Tumbled Glass)
Amorphous Silicon Dioxide (SiO2) with additives
mineraloid (man-made)
Obsidian
Volcanic Glass (Amorphous Silica)
igneous
Obsidian
Obsidian (Volcanic Glass, primarily SiO2)
igneous
Quartzite
Quartzite (primarily SiO2)
metamorphic
Obsidian
Volcanic glass (SiO2 - Silicon dioxide predominant composition)
Igneous
Drill Core Sample
Cylindrical Rock Core (Specific mineralogy varies by extraction site)
Metamorphic (Likely Gneiss or Schist based on texture)
River Pebble (Greywacke or Quartzite-rich Sandstone)
Lithic Sandstone (primarily SiO2 with rock fragments)
sedimentary
Snowflake Obsidian
Spherulitic Obsidian (Amorphous volcanic glass with Phenocrysts of Cristobalite)
igneous
Limonite Pseudomorph after Pyrite
Limonite (Hydrous iron oxides, FeO(OH)·nH2O) replacing Pyrite (FeS2)
mineral
Quartzite
Quartzite (primarily SiO2)
metamorphic
Zebra Rock (Zebra Stone / Ribbon Stone)
Siltstone with Ferruginous Banding (Primarily Quartz, Kaolinite, and Hematite)
sedimentary
Acrylic or Resin (Synthetic Imitation)
Polymethyl Methacrylate (PMMA) or Polyepoxide
Synthetic/Man-made Polymer
Obsidian
Volcanic Glass (70% or more SiO2)
igneous
Bull Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
mineral
Blue Goldstone
Aventurine Glass (Silicon Dioxide infused with Cobalt/Copper)
Synthetic (Man-made Glass)
Quartzite
Quartzite (SiO2)
metamorphic
Opalite
Opalescent Glass (SiO2 + coloring agents)
Mineral (Synthetic/Man-made)
Obsidian
Volcanic Glass (70% or more SiO2)
igneous
Black Obsidian
Volcanic Glass (70–75% SiO2 plus MgO, Fe3O4)
igneous
Limestone
Calcium Carbonate (CaCO3)
sedimentary
Black Obsidian
Obsidian (Amorphous volcanic glass, SiO2)
igneous
Metaconglomerate
Protolith: Conglomerate (comprising SiO2, Al2O3, etc.)
metamorphic