Obsidian
Volcanic Glass (SiO2)
Category
Browse synthetic (man made glass) specimens identified by the Rock Identifier community.
Obsidian
Volcanic Glass (SiO2)
Obsidian (Black Obsidian)
Obsidian (Volcanic Glass)
Obsidian
Volcanic Glass (SiO2)
Black Obsidian
Obsidian (Volcanic Glass)
Obsidian
Volcanic Glass (SiO2)
Obsidian
Obsidian (Volcanic Glass)
Pumice
Vesicular volcanic glass
Clear Quartz Sphere
Crystalline Silicon Dioxide (SiO2)
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Quartz (specifically Milky Quartz Pebble)
Silicon Dioxide (SiO2)
Chert / Flint with Cortex
Silicon Dioxide (SiO2)
Quartz on Greenstone
Silicon Dioxide (SiO2) on Altered Igneous Geologic Unit
Clear Quartz
Silicon Dioxide (SiO2)
Smoky Quartz
Smoky Quartz (Silicon Dioxide - SiO2)
Quartz Crystal (Geode Fragment)
Silicon Dioxide (SiO2)
Quartz (Milky/Smoky variety)
Silicon Dioxide (SiO2)
Sandstone (Weathered / Crushed)
Quartz Sandstone
Quartz Pebble
Silicon Dioxide (SiO2)
Clear quartz sphere or polished quartz cabochon (tentative)
Quartz, silicon dioxide (SiO₂); appearance may also be consistent with ordinary glass, which cannot be ruled out from the image alone
Slag Glass
Amorphous Silica Glass (with metal oxide inclusions)
Sea Glass
Amorphous Silica (Anthropogenic glass) - SiO2
Slag Glass
Glassy Silicate Residue
Fulgurite
Fulgurite (Lechatelierite/Silica glass)
Quartz
Silicon Dioxide (SiO2)
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Green Slag Glass
Amorphous Silicon Dioxide (with metallic impurities)
Yellow Quartzite Pebble
Quartzite (SiO2)
Limestone (River Pebble)
Calcium Carbonate (CaCO3)
Chert (or potentially massive Quartz/Quartzite)
SiO2 (Silicon Dioxide)
Quartz (Milky/Crystalline variety)
Silicon Dioxide (SiO2)
Chert
Microcrystalline quartz (SiO2)
Petrified Wood
Silicified Wood (Permineralized organic tissue)
Citrine (or Yellow Chalcedony / Quartz)
Silicon Dioxide (SiO2)
Tumbled Rose Quartz
Silicon Dioxide (SiO2)
Quartz with Iron Staining
Silicon Dioxide (SiO2) with Hematite/Limonite inclusions
Chert (Flint)
SiO2 (Microcrystalline Quartz)
Chert (variations include Flint/Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Tan/Yellow variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Iron-stained Quartz
Silicon Dioxide with Iron Oxide (SiO2 with Limonite/Hematite impurities)
Chalcedony (Common Opal or Agate variant)
Silicon Dioxide (SiO₂)
Chert (Flint)
Microcrystalline Quartz (SiO2)