Dendritic Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
Category
Browse organic gemstone (not a mineral) specimens identified by the Rock Identifier community.
Dendritic Opal (Common Opal)
Amorphous Hydrated Silica (SiO2·nH2O) with Manganese or Iron Oxide inclusions
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Nuummite
Nuummite (intergrowth of orthoamphiboles Anthophyllite and Gedrite, (Mg,Fe)7Si8O22(OH)2)
Peridot
Olivine (Mg, Fe)₂SiO₄
Brown Jasper (Likely)
Jasper (Cryptocrystalline Silicon Dioxide - SiO2)
Chert / Flint
Chert (varietal name for microcrystalline quartz). Chemical formula: SiO₂
Shale or Slaty Mudstone
Argillaceous sedimentary rock
Yellow Beryl (Heliodor)
Beryllium aluminum silicate (Be3Al2Si6O18)
Aquamarine
Beryl (Be3Al2Si6O18)
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Shale
Fissile Clay-dominant Mudrock (SiO2, Al2O3, K2O, Na2O, CaO, MgO)
Rhodonite
Rhodonite (Manganese silicate, (Mn,Fe,Mg,Ca)SiO3)
Ferruginous Sandstone (with possible trace fossils)
Arenite with Iron-Oxide Cement (SiO2 with Fe2O3)
Rutilated Quartz
Silicon Dioxide (SiO2) with Titanium Dioxide (TiO2) inclusions
Clear Quartz (Rock Crystal)
Silicon Dioxide (SiO2)
Opal
Hydrated silica (SiO2·nH2O)
Chakra Stone Bracelet (mixed gemstones)
Multi-mineral/Gemstone assembly (primarily Quartz variety beads)
Milky Quartz
Silicon Dioxide (SiO2)
Hemimorphite on Limonite Gossan
Hemimorphite (Zn4Si2O7(OH)2·H2O) on Limonite matrix
Dragon Stone
Ohko Stone (Argillaceous sedimentary rock)
Chert (and Jasper/Flint variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Smoky Quartz
Silicon Dioxide (SiO2)
Petrified Wood (Silicified Wood)
Silicified Wood (primarily Chalcedony/Quartz, SiO2)
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
Garnet (Almandine)
Almandine, Fe3Al2(SiO4)3
Sunstone
Heliolite (Sodium Calcium Aluminum Silicate with Iron or Copper inclusions)
Quartz (Clear Quartz/Rock Crystal)
Silicon Dioxide (SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (Grey Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Azurite and Malachite on Matrix
Cu3(CO3)2(OH)2 (Azurite) and Cu2CO3(OH)2 (Malachite)
Amethyst Geode
Silicon Dioxide (SiO2) - Amethyst variety of Quartz
Milky Quartz
Silicon Dioxide (SiO2)
Amethyst
Silicon Dioxide (SiO2) with trace Iron (Fe)
Amethyst
SiO2 (Silicon Dioxide with Iron impurities)
Peridot
Olivine (Mg, Fe)2SiO4
Smoky Quartz
Silicon Dioxide (SiO2)
Mixed Gemstone Beaded Jewelry
Various minerals (e.g., Quartz varieties like Rose Quartz, Amethyst; Peridot; Garnet; etc.)
Quartz Mineral
Silicon Dioxide (SiO2)