Ruby
Corundum (Al2O3 with Chromium traces)
Category
Browse synthetic (man made glass) specimens identified by the Rock Identifier community.
Ruby
Corundum (Al2O3 with Chromium traces)
Cubic Zirconia (Faceted Gemstone)
Zirconium dioxide (ZrO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Quartzite
Metamorphic Quartzite (SiO2)
Chert (varieties include Flint and Mudstone)
Microcrystalline Silica (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Chert (Flint/Chalcedony)
Silicon Dioxide (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Quartzite
Quartzite (SiO2)
Eroded Brick or Pumice-like Scoria
Vesicular Basalt / Scoria (Anthropogenic variant: Eroded Firebrick)
Zircon
Zirconium Silicate (ZrSiO₄)
Iron Slag
Ferrous slag (primarily silicates and oxides of calcium, iron, and magnesium)
Emerald
Beryl (Be3Al2(SiO3)6) with trace Chromium/Vanadium
Emerald
Beryl (Be₃Al₂(SiO₃)‑₆) with Chromium/Vanadium impurities
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (and/or Flint)
Microcrystalline Quartz (SiO2)
Pyrite
Iron Sulfide (FeS2)
Chert (often called Flint or Jasper if reddish)
Microcrystalline Quartz (SiO2)
Gemstone bead necklace (likely citrine or yellow quartz)
Quartz, SiO₂; precise identification is uncertain because the beads are blurred and metal settings obscure them
Staurolite (Fairy Stone)
Staurolite (Fe2+2Al9Si4O23(OH))
Ruby
Corundum (Al2O3 with Chromium impurities)
Malachite
Cu2CO3(OH)2 (Copper Hydroxide Carbonate)
Flint
Silicon dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Ruby
Corundum (Al2O3 with Chromium traces)
Ruby (in jewelry)
Corundum (Al2O3 with Chromium traces)
Bituminous Coal
Organic-rich sedimentary rock (Complex hydrocarbons)
Amethyst (Tumbled/Weathered Quartz)
Amethyst (SiO2 with iron impurities)
Smoky Quartz
Silicon Dioxide (SiO2)
Pearl
Pearl (Calcium Carbonate with organic conchiolin, CaCO3)
Quartzite
Metamorphosed Quartz Sandstone
Chert (Common Variety, Jasper)
Microcrystalline Quartz (SiO2)
Amethyst
Silicon Dioxide (SiO2)
Silicon Carbide (Carborundum)
Silicon Carbide (SiC)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Chert (Microcrystalline Quartz, SiO2)
Red Chert (Jasper)
Cryptocrystalline Quartz (SiO2) with iron oxide inclusions
Emerald
Beryl (Be3Al2Si6O18), specifically the green variety colored by chromium or vanadium
Basalt
Basalt
Diamond
Native Carbon (C)