Amethyst (Quartz)
Amethyst (Silicon Dioxide with Iron impurities, SiO2)
Category
Browse organic gemstone (not a mineral) specimens identified by the Rock Identifier community.
Amethyst (Quartz)
Amethyst (Silicon Dioxide with Iron impurities, SiO2)
Emerald
Beryl (Be3Al2(SiO3)6) with Chromium and/or Vanadium impurities
Amazonite (with smoky quartz/feldspar inclusions)
K(AlSi3O8), Microcline (Tectosilicate)
Quartz in Matrix
Silicon Dioxide (SiO2)
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
Paraiba Tourmaline
Elbaite Tourmaline (Na(Li,Al)3Al6(BO3)3Si6O18(OH)4) - Copper-bearing
Amazonite
Amazonite (KAlSi3O8, a variety of Microcline)
Amethyst Quartz
Amethyst (Silicon Dioxide, SiO2)
Amazonite
K(AlSi3O8), Microcline
Amethyst (Pale/Light Variety)
Quartz (Silicon Dioxide) with Iron impurities - SiO2
Chrysocolla in Matrix
Chrysocolla (Cu,Al)2H2Si2O5(OH)4·nH2O
Amethyst
Crystalline Quartz (SiO2 with iron impurities)
Pearl
Aragonite (CaCO3) with Conchiolin
Chert (often called Flint or Jasper if reddish)
Microcrystalline Quartz (SiO2)
Sandstone Chert Concretion
Silica-cemented Concretion (primarily SiO2)
Blue Tiger's Eye
Crocidolite in Quartz (altered)
Mother of Pearl (Nacre)
Aragonite (layered with organic polymers), CaCO3
Purple Agate (Dyed Chalcedony)
SiO2 (Silicon Dioxide) with organic dyes
Chert Pebble (Jasper/Quartz variety)
Microcrystalline Quartz (SiO2)
Yellow Sapphire or Citrine
Al2O3 (Corundum) or SiO2 (Quartz)
Epidote
{Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH)
Epidote
Epidote ({Ca2}{Al2Fe3+}(Si2O7)(SiO4)O(OH))
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (SiO2)
Quartz Geode in Chert/Limestone Matrix
Silicon Dioxide (SiO2) within Sedimentary Host Rock
Red Jasper
Silicon dioxide (SiO2) with Iron Oxide (Fe2O3) inclusions
Quartz Geode
Silicon Dioxide (SiO2) within a secondary sedimentary structure
Chert (Flint variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (and/or River Pebble)
Microcrystalline quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Tanzanite
Blue Zoisite (Ca2Al3(SiO4)(Si2O7)O(OH))
Blue Apatite
Fluorapatite (Ca5(PO4)3F)
Tahitian Pearl
Biogenic Calcium Carbonate (Aragonite/Calcite), CaCO3
Chert / Flint
Microcrystalline Quartz (SiO2)
Chert (often called Flint)
Cryptocrystalline Quartz (SiO2)
Citrine
Silicon dioxide (SiO2) - yellow quartz variety
Aquamarine
Beryl (Be3Al2Si6O18 with trace Fe2+)
Petrified Wood
Silicified wood (principally Silicon Dioxide, SiO2)
Petrified Wood
Silicified Wood (SiO2)
Blue Chalcedony
Silicon Dioxide (SiO2)