Obsidian
Volcanic Glass (Amorphous Silicon Dioxide, SiO2)
Category
Browse non geological specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide, SiO2)
Obsidian Arrowhead
Volcanic Glass (Primary composition: SiO2)
Siltstone
Siltstone (primarily composed of microcrystalline Quartz and Feldspar)
Quartzite
Quartzite (primarily SiO2)
Obsidian
Volcanic Glass (SiO2, usually 70% or more)
Snowflake Obsidian
Volcanic Glass (SiO2 + impurities)
Quartzite
Quartzite (SiO2)
Quartzite
Quartzite (SiO2)
Obsidian
Volcanic Glass (mostly SiO2)
Peridot
Olivine ((Mg,Fe)2SiO4)
Obsidian
Volcanic Glass (Extrusive Igneous Rock, primarily SiO2)
Quartzite
Quartzite (primarily SiO2)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Obsidian
Volcanic Glass (SiO2)
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2
Unable to identify - Image contains non-geological items
Quartz Vein in Schist
Quartz (SiO2) in Mica Schist
Obsidian
Obsidian (Volcanic Glass)
Obsidian
Volcanic glass (SiO2-rich extrusive igneous rock)
Obsidian
Obsidian (Volcanic Glass; SiO2 content > 70%)
Obsidian
Obsidian (principally SiO2)
Obsidian Arrowhead
Volcanic Glass (70% or more SiO2)
Coquina
Biogenic Limestone (mostly Calcium Carbonate, CaCO3)
Obsidian
Volcanic Glass (predominantly SiO2)
Obsidian
Obsidian (Amorphous volcanic glass, SiO2 rich)
Amber
Succinite (Fossilized Tree Resin)
Opalite
Synthetic Opalised Glass
Obsidian
Obsidian (Volcanic Glass)
Obsidian
Obsidian (principally SiO2)
Obsidian
Volcanic glass (high silica SiO2)
Apache Tears (Obsidian)
Volcanic Glass (SiO2 - Silicon Dioxide with impurities)
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide) with impurities
Dendritic Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
Sandstone (likely a river or beach pebble)
Sandstone (a clastic sedimentary rock)
Obsidian
Obsidian (principally SiO2 with MgO and Fe3O4)
Snowflake Obsidian
Vitreous volcanic silicate (SiO2 with Cristobalite inclusions)
Obsidian
Volcanic Glass (SiO2 + impurities)
Obsidian (in jewelry setting)
Volcanic Glass (Amorphous Silica)
Obsidian
Obsidian (principally SiO2/Silicon dioxide)
Note: Item is a Synthetic/Man-made Object
Titanium-coated Stainless Steel (Fe-Cr-Ni-Ti)
Obsidian
Obsidian (Volcanic Glass)