Sandstone
Clastic Sedimentary Rock
Category
Browse tektite (natural glass) specimens identified by the Rock Identifier community.
Sandstone
Clastic Sedimentary Rock
Tumbled agate (likely Botswana or fortification agate)
Microcrystalline quartz, SiO₂ (chalcedony with banded impurities)
Quartz Pebble
Silicon Dioxide (SiO2)
Quartz (Smoky Quartz variant)
Silicon Dioxide (SiO2)
Jasper with Hematite
Silicon Dioxide (SiO2) with Iron Oxide (Fe2O3)
Citrine
Silicon Dioxide (SiO2)
Slag Glass
Vitreous Silicate Residue
Onyx (beads)
SiO2 (Cryptocrystalline Quartz)
Sand
Siliciclastic sediment / Quartz sand (SiO2)
Quartz Pebble
Silicon Dioxide (SiO2)
Polished blue-banded agate slice
Agate (microcrystalline quartz, SiO₂; chiefly chalcedony)
Smoky Quartz with Inclusions
Silicon Dioxide (SiO2)
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
Green Aventurine
Quartz (Silicon Dioxide) with Fuchsite inclusions (SiO2 + K(Al,Cr)2(AlSi3O10)(OH)2)
Green Aventurine
Silicon Dioxide (Quartz) with inclusions of Fuchsite mica; Chemical formula: SiO2 + K(Al,Cr)2AlSi3O10(OH)2
Green Aventurine
Silicon Dioxide (SiO2) with Fuchsite inclusions
Sandstone (Ferruginous)
Arenite with Iron-Oxide Cement
Sandstone (Micaceous/Feldspathic variant)
Arenite (specifically subarkose or lithic arenite)
Clear Quartz (Tumbled)
Quartz (Silicon Dioxide - SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Quartz (specifically Citrine or Iron-stained Quartz)
Silicon Dioxide (SiO2)
Amethyst (Agate/Chalcedony variety)
Silicon Dioxide (SiO2) with iron impurities
Sandstone (Quartz-rich)
Sandstone (SiO2 dominated)
Limestone
Calcium Carbonate (CaCO3)
Yellow Quartz
Silicon Dioxide (SiO2)
Citrine Quartz (Yellow Quartz)
Silicon Dioxide (SiO2) with iron impurities
Quartz (Smoky/Milky variety)
Silicon Dioxide (SiO2)
Quartz (Smoky/Milky Pebble)
Silicon Dioxide (SiO2)
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Smoky Quartz
Quartz (Silicon Dioxide) - SiO2
Smoky Quartz
Silicon Dioxide (SiO2)
Emerald
Beryl (Be3Al2Si6O18 with chromium and vanadium impurities)
Sedimentary Sandstone with Iron Oxide
Ferruginous Sandstone
Citrine Quartz
Silicon Dioxide (SiO2)
Smoky Quartz
Smoky Quartz (Silicon Dioxide, SiO2)
Smoky Quartz with Hematite inclusions
Silicon Dioxide (SiO2) with Fe2O3 inclusions
Raw emerald-bearing beryl (probable)
Beryl, Be₃Al₂Si₆O₁₈; green color from trace chromium and/or vanadium
Quartz (Smoky Quartz variant)
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Snowflake Obsidian
Vitreous volcanic silicate (SiO2 with Cristobalite inclusions)
Sandstone
Arenite
Sandstone
Arenite (primarily SiO2)