Apache Tears (Obsidian)
Volcanic Glass (SiO2 - Silicon Dioxide with impurities)
Category
Browse organic (non geological) specimens identified by the Rock Identifier community.
Apache Tears (Obsidian)
Volcanic Glass (SiO2 - Silicon Dioxide with impurities)
Fossil Brachiopod
Phylum Brachiopoda
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Obsidian
Volcanic Glass (Primary composition: SiO2 - Silicon Dioxide)
Blue Sapphire (Ceylon)
Corundum (Al2O3) with traces of Iron and Titanium
Petrified Wood
Silicified Wood (primarily SiO2)
Iron-rich quartzite or quartz-bearing metamorphic rock
Quartzite, predominantly SiO₂, with iron-oxide staining (hematite/goethite)
Chert / River Jasper
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (with Quartz Veining)
Chert (formula: SiO2)
Petrified Wood
Silicified Wood (SiO2)
Shale
Shale (fine-grained clastic sedimentary rock)
Limestone (Concretionary or Tufa)
Calcium Carbonate (CaCO3)
Obsidian
Obsidian (principally SiO2)
Obsidian
Volcanic glass (high silica content, usually >70% SiO2)
Chalk
Calcium Carbonate (CaCO3)
Grey and White Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Jasper (Red-Brown)
Silicon Dioxide (SiO2) with Iron Oxide impurities
Chert (Quartz Variety)
Microcrystalline Silica (SiO2)
Chert (specifically Tan/Yellow Chert)
Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)
Moss Agate
Cryptocrystalline Quartz (SiO2 with Manganese or Iron Oxide inclusions)
Ambergris
Ambergris (Coprolite-adjacent organic substance)
Fossils in Limestone (Crinoid / Marine Invertebrate Fossil)
Fossiliferous Limestone (containing Crinoidea / Brachiopoda)
Petrified Wood (Silicified Wood)
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
Petrified Wood
Silicified Wood (SiO2)
Magnetic Hematite
Magnetized Hematite (an iron oxide mineral, Fe2O3, that has undergone magnetization)
Milky Quartz
Silicon Dioxide (SiO2)
Silty Shale or Mudstone
Siltstone/Mudstone (Clastic Sedimentary Rock)
Obsidian
Obsidian (Volcanic glass, primarily SiO2)
Mahogany Obsidian
Obsidian (Volcanic Glass) with Hematite or Magnetite inclusions, SiO2 (Silicon Dioxide)
Chert (Cherty Shale / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Quartzite
Metamorphic Quartzite (primarily SiO2)
Tumbled Obsidian (possibly Mahogany Obsidian variant)
Volcanic Glass (Amorphous Silicon Dioxide, SiO2)
Petrified Wood
Silicified Wood (SiO2)
Fossilized Coral (Petoskey Stone or Tabulate Coral)
Scleractinia or Tabulata (CaCO3 - Calcium Carbonate)
Chert Nodule
Microcrystalline Quartz (SiO2)
Obsidian
Obsidian (principally SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood (SiO2)
Moqui Marble (Shaman Stone)
Iron Oxide Concretion (composed primarily of Quartz sand with Hematite/Goethite shell)
Obsidian
Obsidian (Volcanic Glass), primarily SiO2 (Silicon Dioxide)