Sandstone
Arenite (Siliclastic sedimentary rock)
Category
Browse tektite (natural glass) specimens identified by the Rock Identifier community.
Sandstone
Arenite (Siliclastic sedimentary rock)
Goldstone (Brown/Gold)
Aventurine Glass (Man-made glass with Copper inclusions)
Snowflake Obsidian
Obsidian with Cristobalite inclusions (70-75% SiO2)
Dyed Quartzite
Tumbled Metamorphosed Quartz (SiO2) with artificial pigment
Quartzite pebble
Quartzite (SiO2)
Green Fluorite (likely synthetic or heat-treated for jewelry)
Calcium Fluoride (CaF2)
Strawberry Quartz (or Sunstone / Tumbled Quartz)
Silicon Dioxide (SiO2) with Hematite/Lepidocrocite inclusions
Opalite
Synthetic Opalised Glass
Blue Goldstone
Aventurine Glass (Silicon Dioxide infused with Cobalt/Copper)
Quartz
Silicon Dioxide (SiO2)
Chert (Vuggy or Weathered)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert Concretion (Flint)
Silicon Dioxide (SiO2)
Cullet Glass (Slag Glass)
Amorphous Silicon Dioxide (SiO2) with metallic oxide impurities
Snowflake Obsidian
Volcanic Glass with Cristobalite inclusions (SiO2)
Sandstone or Limestone
Arenite or Calcareous Sedimentary Rock
Sandstone
Arenite (SiO2 primarily)
Colorless faceted gemstone (most likely synthetic cubic zirconia)
Cubic zirconia, ZrO₂ (likely synthetic); natural alternatives include quartz or diamond
Amethyst (Rose-tinted variation)
Silicon Dioxide (SiO2) with trace iron impurities
Apache Tear
Hydrated Obsidian (Natural Volcanic Glass)
Yellow Quartz / Citrine Quartz
Silicon Dioxide (SiO2)
Amethyst cluster
Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation
Quartz pebble
Silicon dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Chert / Flint
Cryptocrystalline quartz (SiO2)
Tumbled blue chalcedony (likely blue quartz/chalcedony)
Cryptocrystalline silica, SiO₂; likely chalcedony, possibly dyed or surface-coated
Sandstone
Arenite (SiO2 based)
Sandstone
Arenite
Sandstone
Arenite (SiO2 primarily)
Sandstone (Quartzose)
Arenite (primarily SiO2)
Sandstone
Arenite (SiO2 based)
Man-made Crystal (Lead Glass)
Lead oxide-doped Silica Glass (approx. SiO2 + PbO)
Quartzite
SiO2 (Silicon Dioxide / Metamorphic Quartz)
Ruby (or potential synthetic/imitation)
Corundum (Al2O3)
Blue Obsidian
Volcanic Glass (SiO2 with inclusions)
Yellow Quartz (Citrine Quartz or Yellow Jasper)
Silicon Dioxide (SiO2) with iron impurities
Smoky Quartz (with Iron Inclusions)
Silicon Dioxide (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Citrine Quartz
Silicon Dioxide (SiO2) with ferric iron impurities
Blue cabochon gemstone, likely sapphire
Corundum (Al₂O₃), blue variety colored mainly by iron and titanium
Citrine Quartz Sphere
Silicon Dioxide (SiO2)
Citrine Quartz
Silicon Dioxide (SiO2)
Opalite
Synthetic glass / Opaque silicious glass