Sandstone (Micaceous Sandstone)
Arenite (SiO2 with KAl2(AlSi3O10)(OH)2 inclusions)
Category
Browse industrial byproduct (often mistaken for obsidian or mineral) specimens identified by the Rock Identifier community.
Sandstone (Micaceous Sandstone)
Arenite (SiO2 with KAl2(AlSi3O10)(OH)2 inclusions)
Quartzite with inclusions
Quartzite (SiO2)
Ferruginous Siltstone or Mudstone
Ferruginous Siltstone / Goethitic Sandstone
Ironstone Concretion
Siderite or Limonite Concretion
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Ironstone Concretion
Ferruginous Sandstone / Iron-rich Sedimentary Rock
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
Limonite Concretion
Limonite (Hydrated Iron Oxide) FeO(OH)·nH2O
Ambergris
Ambra grisea (Metabolic byproduct)
Aventurine
Silicon Dioxide (SiO2) with inclusions
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Obsidian
Volcanic Glass (SiO2)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Obsidian (Black)
Obsidian (High-silica volcanic glass)
Mahogany Obsidian
Obsidian (SiO2 + Fe2O3)
Ironstone Concretion (Siderite Nodules)
Siderite (FeCO3) in Mudstone or Sandstone matrix
Pyrite (Fool's Gold)
Iron Disulfide (FeS2)
Dumortierite Quartz
Al7(BO3)(SiO4)3O3
Obsidian
Volcanic glass (SiO2)
Sandstone with Dendritic Manganese Oxides
Sandstone (SiO2 predominant) with Oxide Dendrites (MnO2)
Mahogany Obsidian
Volcanic glass (Silicon Dioxide with Hematite/Magnetite inclusions)
Green Aventurine
Aventurine Quartz (SiO2 with inclusions of Fuchsite mica)
Black Spinel
Magnesium Aluminum Oxide (MgAl2O4)
Sodalite
Sodalite (Na8(Al6Si6O24)Cl2)
Obsidian
Obsidian (Volcanic Glass)
Concretion
Septarian concretion (likely containing Calcite or Siderite)
Dendritic Jasper (River Stone)
Silicon Dioxide (SiO2) with Manganese/Iron Oxide inclusions
Strawberry Quartz (Aventurine)
Silicon Dioxide with Hematite/Lepidocrocite inclusions (SiO2)
Dendritic Agate (River Pebble)
Silicon Dioxide (SiO2) with Manganese or Iron oxide inclusions
Green Aventurine
Aventurine Quartz (SiO2 with Fuchsite inclusions)
Pink and Green Tourmaline (Tumbled)
Elbaite (Na(Li,Al)3Al6(BO3)3Si6O18(OH)4)
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Black Obsidian
Volcanic Glass (predominantly SiO2, Silicon Dioxide)
Obsidian
Volcanic Glass (comprised primarily of SiO2)
Blue Apatite
Fluorapatite / Chlorapatite [Ca5(PO4)3(F,Cl,OH)]
Snowflake Obsidian (Flower Jasper variant)
Vitreous volcanic silicate with cristobalite inclusions
Black Tourmaline
Schorl (Na(Fe2+)_{3}Al_{6} (BO_{3})_{3} (Si_{6}O_{18})(OH)_{4})
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Blue Dumortierite in Quartz
Al7(BO3)(SiO4)3O3 (Dumortierite)
Obsidian
Obsidian (Volcanic Glass)