Amethyst
Silicon Dioxide (SiO2) with Iron impurities
Category
Browse metamorphic, likely sedimentary with quartz veins specimens identified by the Rock Identifier community.
Amethyst
Silicon Dioxide (SiO2) with Iron impurities
Blue Chalcedony
Silicon Dioxide (SiO2)
Graphite
Graphite (Native Carbon, C)
Shale or Slaty Mudstone
Argillaceous sedimentary rock
Fossiliferous Limestone
Fossiliferous Limestone (CaCO3)
Mixed Tumbled Gemstones and River Rocks
Mixed Decorative Stones (predominantly Silicon Dioxide - SiO2 variants)
Chert (or Flint)
Chert (a cryptocrystalline variety of quartz, SiO2)
Citrine (Yellow Quartz)
Silicon Dioxide (SiO2)
Green Aventurine
Silicon Dioxide (Quartz) with inclusions of Fuchsite mica (K(Al,Cr)2(AlSi3O10)(OH)2)
Green Aventurine
Silicon Dioxide (SiO2) with inclusions of Fuchsite mica
Mica-rich Sandstone or Micaceous Schist Weathering
Micaceous Schist (Muscovite-Quartz composition)
Quartz (Milky/Yellowish)
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Orange Calcite
Calcite (Calcium Carbonate - CaCO3)
Petrified Wood
Silicified wood (Quartz, SiO2)
Calcite (or Alabaster, if truly carved)
Calcium Carbonate (CaCO3)
Quartzite
Quartzite (primarily SiO2)
Quartz (Milky/Crystal variety)
Silicon Dioxide (SiO2)
Blue Sapphire
Corundum (Al2O3 - Aluminum Oxide with Iron and Titanium impurities)
Muscovite Schist
Muscovite (KAl2(AlSi3O10)(OH)2) in Schist
Tiger's Iron
Pseudomorphic Quartz Aggregate (contains SiO2 with Fe2O3 and FeOOH)
Quartz Druzy on Matrix (likely Agate or Jasper)
Silicon Dioxide (SiO2) with various mineral inclusions
Gneiss
Gneiss (High-grade Metamorphic Rock)
Chert Pebble (Jasperoid/Flint)
Silicon Dioxide (SiO2) - cryptocrystalline quartz
Quartz Pebble
Silicon Dioxide (SiO2)
Sandstone (likely Siltstone variety)
Arenite / Siltstone (primary mineral SiO2)
Blue Apatite
Apatite - Ca5(PO4)3(F,Cl,OH) (Calcium phosphate with Fluorine, Chlorine, or Hydroxyl)
Zebra Jasper
Tetragonal Silicon Dioxide (Quartz) with impurities
Gneiss (Metamorphic Rock)
Gneiss (high-grade regional metamorphic rock)
Quartz Pebble (Citrine-colored or Stained Quartz)
Silicon Dioxide (SiO2)
Almandine Garnet in Matrix
Almandine Garnet (Fe3Al2(SiO4)3) in Schist/Quartz Matrix
Jade (likely Nephrite Jade based on appearance)
Nephrite (a variety of actinolite, Ca2(Mg,Fe)5Si8O22(OH)2)
Ferruginous Quartz (River Pebble)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Orange Calcite
Calcium Carbonate (CaCO3)
Pyrite
Iron Disulfide (FeS2)
Rough Emerald (Beryl)
Emerald (Be3Al2(SiO3)6 with Cr/V impurities)
Calcite
Calcium Carbonate (CaCO3)
Lapis Lazuli (Low-grade/Calcite-heavy)
Na8[Al6Si6O24]n(S,Cl,SO4,OH)2 (Lazurite component)
Jasper Conglomerate (Puddingstone)
Siliceous Conglomerate (Quartz and Jasper clasts in a fine-grained matrix)
Galena
Lead Sulfide (PbS)
Pyrite
Iron Sulfide (FeS2)
Granite (weathered cobble)
Granite