Quartzite
Quartzite (SiO2)
Category
Browse man made byproduct (non geological) specimens identified by the Rock Identifier community.
Quartzite
Quartzite (SiO2)
Quartzite
Quartzite (SiO2)
Obsidian
Volcanic Glass (SiO2, usually 70% or more)
Chert
Chert (microcrystalline quartz)
Black Obsidian with white veins
Volcanic Glass (70–75% SiO2)
Magnetic Hematite
Magnetized Hematite (an iron oxide mineral, Fe2O3, that has undergone magnetization)
Snowflake Obsidian
Volcanic Glass (SiO2 + impurities)
Basalt
Basalt
Marble
Marble (metamorphosed limestone or dolostone), primarily composed of calcite (CaCO3) or dolomite (CaMg(CO3)2)
Obsidian
Volcanic Glass (Extrusive Igneous Rock, primarily SiO2)
Obsidian
Volcanic Glass (mostly SiO2)
Quartzite
Quartzite (primarily SiO2)
Quartz (Iron-stained)
Silicon Dioxide (SiO2) with Hematite/Limonite impurities
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2
Quartzite pebble
Quartzite (primarily SiO2)
Obsidian
Volcanic Glass (SiO2)
Obsidian
Obsidian (Volcanic Glass, SiO2 + impurities)
Granite (weathered pebble)
Granite (plutonic igneous rock)
Amber
Succinite (Fossilized Tree Resin)
Obsidian
Obsidian (Volcanic Glass; SiO2 content > 70%)
Metallic Ornament / Jewelry
N/A - This is an artificial object, not a geological specimen.
Obsidian
Volcanic Glass (predominantly SiO2)
Obsidian
Obsidian (Volcanic Glass)
Obsidian
Volcanic glass (SiO2-rich extrusive igneous rock)
Obsidian
Obsidian (Volcanic Glass)
Obsidian
Obsidian (principally SiO2)
Obsidian Arrowhead
Volcanic Glass (70% or more SiO2)
Obsidian
Obsidian (Amorphous volcanic glass, SiO2 rich)
Limonite
Hydrous Iron Oxide (often Goethite FeO(OH), Lepidocrocite γ-FeO(OH), and other amorphous iron oxyhydroxides)
Dendritic Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
Obsidian
Volcanic glass (high silica SiO2)
Chert Pebble/Nodule
Chert (a microcrystalline or cryptocrystalline sedimentary form of quartz, SiO2)
Black Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide) with impurities
Obsidian
Obsidian (principally SiO2 with MgO and Fe3O4)
Snowflake Obsidian
Vitreous volcanic silicate (SiO2 with Cristobalite inclusions)
Obsidian
Volcanic Glass (SiO2 + impurities)
Garnet (Almandine variety)
Almandine, Fe3Al2(SiO4)3
Obsidian (in jewelry setting)
Volcanic Glass (Amorphous Silica)
Obsidian
Obsidian (principally SiO2/Silicon dioxide)
Obsidian
Obsidian (Volcanic Glass)
Clay (as a rock-forming material)
Clay minerals (e.g., Kaolinite group, Smectite group, Illite group, Chlorite group)