Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 staining)
Category
Browse tektite (natural glass) specimens identified by the Rock Identifier community.
Sandstone (Ferruginous)
Arenite (composed primarily of SiO2 with Fe2O3 staining)
Blue Topaz
Aluminum Silicate Fluoride Hydroxide Al2SiO4(F,OH)2
Polished blue agate/geode slice
Chalcedony (microcrystalline quartz, SiO₂), likely dyed blue
Amethyst Cluster
Silicon Dioxide (Quartz variety: Amethyst) - SiO2
Tumbled pale stone, likely milky quartz or calcite
Quartz (SiO₂) or calcite (CaCO₃); exact identification requires testing
Citrine
Silicon dioxide (SiO2) - yellow quartz variety
Pumice
Extrusive volcanic rock (Vesicular Rhyolite/Dacite/Andesite)
Rough Emerald/Green Beryl
Beryl (Be3Al2(SiO3)6) with trace amounts of Chromium or Vanadium
Sandstone
Arenite
Likely polished dark pebble
Indeterminate; possibly basalt, black jasper, or a dark sulfide-rich stone
Amethyst Cluster
Silicon Dioxide (SiO2 with iron impurities)
Pink granite
Felsic intrusive igneous rock; mainly quartz, potassium feldspar, plagioclase, and minor mica
Amethyst Quartz with Matrix
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Smoky Quartz
Smoky Quartz (Silicon Dioxide - SiO2)
Herkimer Diamond
Quartz (Silicon Dioxide, SiO2)
Herkimer Diamond
Quartz (Silicon Dioxide) - SiO2
Herkimer Diamond
Quartz (Silicon Dioxide - SiO2)
Yellow Topaz (Imperial or Precious Topaz)
Al2SiO4(F,OH)2 (Aluminum Silicate Fluoride Hydroxide)
Amethyst geode slices
Amethyst, purple quartz (SiO₂)
Red Granite
Felsic intrusive igneous rock (K-feldspar rich Granite)
Pink Granite
Granite (Felsic Plutonic Rock)
Polished dark chert or flint
Microcrystalline quartz (SiO₂), commonly called chert; possibly flint
Raw Sapphire (Corundum)
Aluminum oxide (Al2O3)
Amethyst
Crystalline Quartz (SiO2 with iron impurities)
Amethyst
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Yellow Jasper
Silicon Dioxide (SiO2) with iron hydroxides
Red Jasper
Silicon Dioxide with Iron Oxide (SiO2 + Fe2O3)
Milky Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Red Chert (Jasper)
Microcrystalline Quartz (SiO2)
Jasper (specifically Bloodstone/Heliotrope or Dark Green Jasper)
Cryptocrystalline Quartz (SiO2) with inclusions
Jasper (Mookaite style)
Jasper (Silica-rich Microcrystalline Quartz, SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Yellow Jasper
Silicon Dioxide with Limonite/Goethite inclusions (SiO2)
Yellow Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Yellow Jasper
Silicon Dioxide (SiO2) with iron hydroxides (Goethite)
Jasper
Silicon dioxide (SiO2) with iron inclusions
Red Jasper with Quartz Veining
Silicon Dioxide (SiO2) with Hematite impurities
Red Jasper (Chert)
Silicon Dioxide (SiO2)