Amethyst
Amethyst (Silicon Dioxide - SiO2 with impurities of Fe3+)
Category
Browse organic gemstone (not a rock) specimens identified by the Rock Identifier community.
Amethyst
Amethyst (Silicon Dioxide - SiO2 with impurities of Fe3+)
Carnelian Agate
Silicon Dioxide (SiO2)
Quartzite
Quartzite (SiO2)
Carnelian
Carnelian (SiO2 - Silicon Dioxide with Iron Oxide impurities)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Fluorite
Calcium Fluoride (CaF2)
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
Yellow Quartz (Citrine Quartz or Yellow Chalcedony)
Silicon Dioxide (SiO2)
Shungite
Non-crystalline carbon (Fullerenes / Carbon-60)
Greywacke
Greywacke (Lithofeldspathic Sandstone)
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
Blue Calcite
Calcium Carbonate (CaCO3)
Metal Chain Belt with Square Plates
Not applicable (man-made)
Chert (often called Flint or River Stone)
Chert (Microcrystalline Silicon Dioxide, SiO2)
Kyanite
Kyanite (Al2SiO5)
Basalt Pebble
Aphanitic mafic volcanic rock
Quartzite
Quartzite (primarily SiO2)
N/A - Man-made object (Jewelry Chain)
Antiqued or Oxidized Metal Chain (often Steel or Brass)
Talc
Talc (Mg₃Si₄O₁₀(OH)₂)
Limonite Sandstone
Ferruginous Sandstone (Hydrated Iron Oxide)
Sugilite
Sugilite (KNa2(Fe,Mn,Al)2Li3Si12O30)
Quartzite
Quartzite (primarily SiO2)
Note: No specimen visible
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Yellow Chalcedony (Agate/Chert)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
Pet Rock (Man-made Quartzite or Granite Cobble)
Silicon dioxide (SiO2) mixture; commonly composed of Quartz, Feldspar, and Mica
Yellow Jasper
Silicon Dioxide (SiO2) with Goethite/Iron oxide inclusions
Red Jasper
Jasper (Silicon Dioxide with Iron Oxide inclusions - SiO2)
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Obsidian
Volcanic Glass (SiO2, usually >70% silica content)
Carved Mottled Greenish-Yellow Crystal/Glass Object
Unknown; possibly a form of quartz (chalcedony/jadeite/nephrite) or glass/resin.
Iridium sand or Osmium-Iridium nugget
Iridosmine / Osmiridium (Platinoid grouping)
Red Jasper (with Quartz inclusions)
Silicon Dioxide (SiO2)
Diamond
Native Carbon (C)
Jade (likely Nephrite or Jadeite)
Nephrite (Ca2(Mg,Fe)5Si8O22(OH)2) or Jadeite (Na(Al,Fe3+)Si2O6)
Carnelian
Carnelian (a variety of Chalcedony, SiO2)
Quartz (Rose or Milky variety fragment)
Silicon Dioxide (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Native Gold (in Jewelry)
Gold (Au)
Fluorite (tumbled pebble)
Calcium Fluoride (CaF2)
Amethyst
Silicon Dioxide with Iron impurities (SiO2)
Quartzite
Quartzite (SiO2)