Obsidian
Volcanic Glass (70% or more SiO2)
Category
Browse industrial byproduct (often mistaken for obsidian or mineral) specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass (70% or more SiO2)
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Obsidian
Obsidian (Amorphous volcanic glass, predominantly SiO2)
Obsidian
Obsidian (Volcanic Glass) SiO2 (70% or more)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Yellow Aventurine
Silicon Dioxide with inclusions (SiO2)
Green Aventurine
SiO2 (Silicon Dioxide with Fuchsite inclusions)
Quartz (Iron-stained or Milky)
Silicon Dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Obsidian
Volcanic Glass (Amorphous Silica)
Banded Sandstone
Arenite (with iron oxide banding)
Arfvedsonite in Quartz
Arfvedsonite [Na3(Fe2+4Fe3+)Si8O22(OH)2] often hosted in Quartz or Feldspar
Dendritic Agate
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Flesh-colored Quartz Mineral
SiO2 (Silicon Dioxide) with Iron Impurities
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Obsidian
Obsidian (Volcanic glass), SiO2 (70% or more)
Obsidian
Volcanic Glass (SiO2 + impurities)
Apache Tear
Obsidian (Hydrated Volcanic Glass - SiO2)
Mahogany Obsidian
Volcanic glass (SiO2 with Hematite or Magnetite inclusions)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Obsidian
Obsidian (Amorphous volcanic glass)
Dendritic Limestone
Calcite with Manganese Oxide (Manganese Dendrites)
Dendrite (Manganese Oxide Dendrites)
Psilomelane or Pyrolusite on Matrix (typically MnO2)
Milky Quartz with Dendritic Inclusions
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Dumortierite Quartz
Al7BO3(SiO4)3O3 (inclusion in SiO2)
Sulfur
Native Sulfur (S)
Blue Dumortierite Quartz
Dumortierite in Quartz (AlAl6BSi3O12(O,OH)3)
Snowflake Obsidian
Vitreous volcanic silicate (SiO2 with Cristobalite inclusions)
Siltstone
Siltstone (SiO2, Fe2O3, Al2O3 mix)
Chrysoprase
Chalcedony (Silicon Dioxide, SiO2), flavored by Nickel
Dumortierite Quartz
Al7BO3(SiO4)3O3 (Aluminum borate silicate)
Sodalite
Na8(Al6Si6O24)Cl2
Golden Sheen Obsidian
Obsidian (volcanic glass) with inclusions of gas bubbles and mineral crystals (e.g., hematite, magnetite) causing the sheen
Obsidian
Amorphous volcanic glass (principally SiO2)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Red Jasper
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Obsidian
Obsidian (Volcanic Glass)
Obsidian
Volcanic Glass (SiO2)
Obsidian
Obsidian (Volcanic Glass)
Obsidian
Amorphous volcanic glass (primarily SiO2)
Obsidian
Obsidian (Volcanic Glass)