Chert (specifically White Chert or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Category
Browse man made silicate (anthropogenic glass) specimens identified by the Rock Identifier community.
Chert (specifically White Chert or Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Lazulite
Lazulite (Mg,Fe2+)Al2(PO4)2(OH)2
Quartzite Pebble
Metamorphosed Quartz Sandstone (SiO2)
Soapstone
Steatite (primarily composed of Talc, Mg₃Si₄O₁₀(OH)₂)
Red Sandstone
Arenite (with Iron Oxide / Hematite staining)
Rose Quartz (likely carved)
Rose Quartz (SiO2)
Ferruginous Sandstone (Ironstone)
Clastic Sedimentary Rock (composed of SiO2 with Fe2O3/FeO(OH) cement)
Bog Iron / Limonite Concretion
Goethite/Limonite mixture (FeO(OH)·nH2O)
Granite
Granite (felsic intrusive igneous rock)
Banded Calcite or Travertine
Calcium Carbonate (CaCO3)
Coral Rock (Coquina)
Biogenic Limestone (Calcium Carbonate - CaCO3)
Quartz
Quartz (SiO₂)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Granite
Granite (a common rock type, not a single mineral with a formula. Composed primarily of quartz, feldspar, and mica/amphibole).
Quartz Vein in Host Rock (Gabbro or Basalt)
Silicon Dioxide (SiO2) with Mafic Silicates
Picture Jasper
Silicon Dioxide (SiO2) with iron oxide and clay inclusions
Green Slag Glass (Cullet)
Amorphous Silica (Industrial Glass Byproduct)
Milky Quartz
Silicon Dioxide (SiO2)
BROWN GRANITE (likely 'Tan Brown' or similar)
Granite (specifically a variety rich in orthoclase feldspar, often with biotite and possibly hornblende)
Obsidian
Obsidian (Volcanic Glass)
Obsidian
Volcanic glass (high silica volcanic rock)
Chalcedony (Common Opal/Chert variety)
Silicon Dioxide (SiO2)
Ferruginous Sandstone
Sandstone, Iron-rich
Quartzite
Quartzite (SiO2)
Apache Tear
Obsidian (Hydrated Silica / Amorphous Volcanic Glass)
Milky Quartz
Silicon Dioxide (SiO2)
Chert (Flint)
Chert (predominantly SiO₂ - silicon dioxide)
Quartz Pebble (often referred to as 'Sea Glass' or 'River Stone' when worn smooth)
Silicon Dioxide (SiO2)
Sandstone
Arenite (SiO2 principal)
Granite
Granite
Obsidian
Amorphous volcanic glass (SiO2)
Sandstone or Limestone
Arenite or Calcareous Sedimentary Rock
Quartzite with Iron Inclusions
Quartzite (primarily SiO2 with Fe2O3 impurities)
Quartz
Quartz (SiO₂)
Greasy Quartz (likely carved Milky Quartz or Aventurine)
Silicon Dioxide (SiO2)
Sandstone
Arenite (primarily SiO2)
River Quartz Cobble
Silicon Dioxide (SiO2)
Seraphinite
Clinochlore (Mg,Fe)5Al(AlSi3O10)(OH)8 - specific variety for Seraphinite due to its fibrous inclusions and chatoyancy.
Quartzite Pebble
Metamorphosed Quartz Sandstone (SiO2)
Quartzite pebble
Quartzite (primarily SiO2)
Sandstone (Quartzose)
Arenite (primarily SiO2)