Jasper (or possibly Agate/Chalcedony) beads
SiO2 (Silicon Dioxide)
Category
Browse synthetic glass specimens identified by the Rock Identifier community.
Jasper (or possibly Agate/Chalcedony) beads
SiO2 (Silicon Dioxide)
Clear Quartz (Faceted)
SiO2 - Silicon Dioxide
Quartzite Pebble (River Rock)
Quartzite (SiO2)
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Iron Slag
Ferrous slag (primarily silicates and oxides of calcium, iron, and magnesium)
Iron-stained quartz-rich rock, possibly quartzite or hydrothermal quartz
Quartz (SiO₂), likely with iron oxides; exact host rock uncertain from the photograph
Obsidian
Amorphous volcanic glass (SiO2)
Weathered quartz-rich rock, possibly pegmatite or quartzite
Quartz (SiO₂)-rich aggregate; exact identification is uncertain from the photograph
Gemstone bead necklace (likely citrine or yellow quartz)
Quartz, SiO₂; precise identification is uncertain because the beads are blurred and metal settings obscure them
Clear Quartz (Carved Dragon)
Quartz (Silicon Dioxide, SiO2)
Blue Aura Quartz
Silicon Dioxide (SiO2) with metallic vapor coating
Red Jasper
Jasper (Silicon Dioxide, SiO2)
Chert / Flint Nodule
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Red Jasper
Jasper (Silicate Mineral), SiO2 with Fe2O3 inclusions
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Polished black stone, likely black obsidian
Obsidian — volcanic glass, chiefly SiO₂
Pumice
Pumice (Vesicular volcanic glass)
Quartz Pebble
Crystalline Silicon Dioxide (SiO2)
Obsidian
Volcanic Glass (Amorphous Silicon Dioxide)
Polished agate geode slice
Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide coloration
Polished yellow jasper or opaque chalcedony bead
Microcrystalline quartz (SiO₂), likely iron-oxide-stained jasper
Pumice
Pumice (Vesicular Felsic Igneous Rock)
Pumice
Pumice (Vesicular volcanic glass)
Snowflake Obsidian
Volcanic glass containing Spherulites (SiO2)
Obsidian
Volcanic Glass (SiO2 + impurities)
Quartz (Clear Quartz)
Silicon Dioxide (SiO2)
Obsidian
Volcanic glass (SiO2-rich)
Libyan Desert Glass
Impactite silica glass (SiO2)
Blue Slag Glass
Ferro-silicate glass (Slag)
Opalite (Man-made Glass)
Fused glass (typically made of dolomite and metal opacifiers)
Fulgurite
Fulgurite (Lechatelierite-rich fused silica)
Clear Quartz (Rock Crystal) Bracelet
Silicon Dioxide (SiO2)
Dragon Vein Agate (Dyed/Fractured Quartz)
Silicon dioxide (SiO2)
Black Onyx
Chalcedony (Silicon Dioxide, SiO2)
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Quartz (Tumbled)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz (Smoky Quartz)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Sandstone
Sedimentary Rock (Quartzose Sandstone)