Green Quartz (including Prase or Aventurine variants)
Silicon Dioxide (SiO2) with inclusions (likely Actinolite or Chlorite)
Category
Browse tektite (natural glass) specimens identified by the Rock Identifier community.
Green Quartz (including Prase or Aventurine variants)
Silicon Dioxide (SiO2) with inclusions (likely Actinolite or Chlorite)
Sandstone (with Iron Staining)
Arenite (composed primarily of SiO2 with Fe2O3 staining)
Clear Quartz
Silicon Dioxide (SiO2)
Chert (specifically Blue Chert/Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Amethyst (Chevron or Banded Amethyst)
Silicon Dioxide (SiO2 with iron impurities)
Amethyst Lace Agate / Banded Amethyst
Silicon Dioxide (SiO2) with Fe3+ impurities
Smoky Quartz
SiO2 (Silicon Dioxide)
Yellow Quartz (Citrine Quartz or Yellow Chalcedony)
Silicon Dioxide (SiO2)
Clear Quartz
Silicon Dioxide (SiO2)
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
Yellow Quartz (Citrine/Lemon Quartz)
Silicon Dioxide (SiO2)
Clear Quartz
Quartz (Silicon Dioxide, SiO2)
Sapphire
Corundum (Al2O3)
Smoky Quartz
Smoky Quartz (Silicon Dioxide - SiO2)
Blue Sapphire
Corundum (Al2O3 with trace Titanium and Iron)
Amethyst
Amethyst (Silicon Dioxide with iron impurities, SiO2)
Amethyst
SiO2 (Silicon Dioxide) - Purple variety of Crystalline Quartz
Sandstone
Arenite (composed primarily of SiO2)
Strawberry Quartz (Hematoid Quartz)
Silicon Dioxide with Hematite inclusions (SiO2 + Fe2O3)
Black Onyx
Onyx (Silicon Dioxide, SiO2)
Sandstone
Sandstone (lithified quartz arenite, arkose, graywacke, etc. depending on composition)
Sandstone
Arenite (composed primarily of SiO2)
Sandstone (Pebble)
Sandstone (arenite, arkose, wacke depending on composition)
Smoky Quartz on Matrix
Silicon Dioxide (SiO2) with trace impurities and aluminum inclusions
Sandstone (likely Quartzose)
Arenite (primarily SiO2)
Amethyst
Amethyst (SiO2 - Silicon Dioxide with iron impurities)
Slag
Ferrous Slag (Siliceous industrial waste)
Quartz (Smoky Quartz variant)
Silicon Dioxide (SiO2)
Black Onyx
Silicon Dioxide (SiO2)
Blue Agate (Tumbled and Dyed)
Silicon Dioxide (SiO2) with likely organic dyes
Sandstone (Ferruginous)
Clastic Sedimentary Rock (primarily SiO2 with Fe2O3 staining)
Obsidian
Obsidian (volcanic glass, amorphous silica rich rock)
Corundum (Sapphire/Ruby in Matrix)
Aluminium oxide (Al2O3)
Smoky Quartz
SiO2 (Silicon Dioxide)
Black Obsidian
Obsidian, volcanic glass (Amorphous SiO₂)
Orange Quartzite
Quartzite (primarily SiO2 with Hematite impurities)
Chert (Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Clear Quartz
Silicon Dioxide (SiO2)
Ferruginous Quartz
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Amethyst
Amethyst (Silicon Dioxide with Iron impurities), SiO2
Jadeite and Mixed Gemstones (Ruby, Sapphire, Emerald)
Jadeite (NaAlSi2O6), Corundum (Al2O3), Beryl (Be3Al2(Si6O18))
Sandstone Beach Pebble
Clastic Sedimentary Rock (primarily Quartz with Iron Oxide coating)