Carnelian
Carnelian (a variety of Chalcedony, SiO2)
Category
Browse organic gemstone (not a rock) specimens identified by the Rock Identifier community.
Carnelian
Carnelian (a variety of Chalcedony, SiO2)
Quartz on Greenstone
Silicon Dioxide (SiO2) on Altered Igneous Geologic Unit
Red Jasper
Silicon Dioxide (SiO2) - variety of Chalcedony
Amethyst and Citrine (Ametrine Mix)
Silicon Dioxide (SiO2) with Fe3+ impurities
Obsidian
Volcanic glass (high silica content, usually >70% SiO2)
Jasper (Iron-stained Chert)
Silicon Dioxide (SiO2) with impurities of Iron Oxide
Moss Agate
Moss Agate (a variety of Chalcedony, SiO ₂)
Greenstone
Chlorite schist / Meta-basalt
Amethyst
Silicon Dioxide (SiO2) with iron impurities
Pearl
Aragonite (CaCO3) with Conchiolin
Amber (Black)
Amber (succinite, retinite, etc., specifically, heavily included/dark varieties)
Amethyst/Smoky Quartz Cluster
Silicon Dioxide (SiO2)
Greenschist
Greenschist (Chlorite-actinolite schist)
Obsidian
Volcanic glass (SiO2 - Silicon Dioxide with impurities)
Carnelian
Silicon Dioxide (SiO2) - variety of Chalcedony
Citrine
Silicon dioxide (SiO2)
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2)
Fluorite (Purple/Blue variety)
Calcium Fluoride (CaF2)
Amethyst (Digital/Conceptual Representation)
Amethyst (Silicon Dioxide with iron impurities, SiO2)
Amethyst
Amethyst (Silicon Dioxide - SiO2 with ferric iron impurities)
Amethyst
Silicon Dioxide (SiO2) containing Iron impurities
Limonite (Iron Ore)
Hydrous ferric oxides (FeO(OH)·nH2O)
Amethyst (Geode Fragment)
Silicon Dioxide (SiO2 with iron impurities)
Jasper (var. Ocean or Polychrome Jasper)
Silicon Dioxide (SiO2) with iron and mineral inclusions
Emerald
Beryl (Be₃Al₂Si₆O₁₈), specifically the green variety colored by trace amounts of chromium or vanadium.
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Chert (often called Flint or Jasper)
Silicon Dioxide (SiO2)
Red Jasper (possibly Chert/Argillite)
Jasper (SiO2) with iron oxide inclusions
Clear Quartz (Tumbled)
Silicon Dioxide (SiO2)
Mica Schist with Quartz
Mica-Quartz Schist (Muscovite subclass)
Crushed Limestone
Calcium Carbonate (CaCO3)
Schist
Mica Schist (primarily Muscovite or Biotite sheet silicates)
Jasper (specifically Picture Jasper or Landscape Jasper)
Silicon Dioxide (SiO2) - Opaque variety of Chalcedony/Quartz
Quartzite
Quartzite (SiO2)
Red Jasper
Jasper (Silicon Dioxide, SiO2 with iron oxide impurities)
Mica Schist
Mica Schist (Composition typically contains Muscovite: KAl2(AlSi3O10)(OH)2 or Biotite: K(Mg,Fe)3AlSi3O10(OH)2 along with Quartz and Feldspar)
Milky Quartz (Gold-bearing Prospecting Specimen)
Silicon Dioxide (SiO2)
Moonstone
Orthoclase Feldspar (KAlSi3O8)
Schist (Biotite Schist)
Biotite-bearing Schist (K(Mg,Fe)3AlSi3O10(F,OH)2)
Apatite
Apatite group mineral (e.g., Fluorapatite - Ca5(PO4)3F, Chlorapatite - Ca5(PO4)3Cl, Hydroxylapatite - Ca5(PO4)3(OH))
Rose Quartz (likely carved)
Rose Quartz (SiO2)
Blue Goldstone
Aventurine Glass