Amethyst
Quartz (Silicon Dioxide with Iron impurities), SiO2
Category
Browse not a geological specimen specimens identified by the Rock Identifier community.
Amethyst
Quartz (Silicon Dioxide with Iron impurities), SiO2
Amazonite
KAlSi3O8 (Potassium aluminum silicate - blue-green variety of Microcline)
Arfvedsonite in Quartz
Arfvedsonite [Na3(Fe2+4Fe3+)Si8O22(OH)2] often hosted in Quartz or Feldspar
Sunstone
Oligoclase (Plagioclase Feldspar), (Ca,Na)(Al,Si)4O8
Quartz (Milky/Iron-stained)
Silicon Dioxide (SiO2)
Milky Quartz with Nephrite Jade
Silicon Dioxide (SiO2) with Ca2(Mg,Fe)5Si8O22(OH)2
Olivine in Basalt
Peridotite / Forsterite ((Mg,Fe)2SiO4)
Prehnite
Prehnite (Ca2Al(AlSi3O10)(OH)2)
Amethyst (Tumbled)
Amethyst (Silicon Dioxide with Iron impurities), SiO2
Amazonite
Potassium Aluminum Silicate (KAlSi3O8)
Chalcedony (Agate Pebble)
Silicon Dioxide (SiO2)
Ocean Jasper or Orbicular Jasper
SiO2
Petrified Wood
Silicified Wood (SiO2)
Amethyst
Silicon Dioxide (SiO2) with trace Iron (Fe3+)
Agate
Silicon Dioxide (SiO2)
Prehnite
Prehnite, Ca2Al2Si3O10(OH)2
Quartz Crystal Fragment
Silicon Dioxide (SiO2)
Fossilized Shell in Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Moonstone (specifically Rainbow Moonstone / White Labradorite)
White Labradorite (Feldspar Group: (Na,Ca)(Al,Si)4O8)
Jasper
Silicon Dioxide (SiO2)
Blue Dyed Agate
Silicon Dioxide (SiO2) with artificial pigment
Dyed Blue Agate Geode Slice
Chalcedony (Silicon Dioxide, SiO2)
Quartzite
Quartzite (primarily SiO2)
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
Chert (Common Opal/Chalcedony mixture)
Silicon Dioxide (SiO2)
Granite Pebble
Felsic Igneous Rock (Granitic composition)
Chert (Jasper variety)
Microcrystalline Quartz (SiO2)
Milky Quartz
Silicon Dioxide (SiO2)
Sandstone (with Limonite staining)
Arenite (primarily SiO2 with FeO(OH)·nH2O)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz (Milky/Smoky variety)
Silicon Dioxide (SiO2)
Quartz with Chalcopyrite and Pyrite
Silicon Dioxide (SiO2) with Copper Iron Sulfide (CuFeS2)
Chalcedony (or a variety of Chalcedony, likely Agate or Jasper)
Chalcedony (SiO₂)
Ironstone Concretion (Limonite/Goethite)
Ferruginous concretion (Fe2O3·nH2O)
Citrine Quartz
Silicon Dioxide (SiO2)
Quartz (Iron-stained)
Silicon Dioxide (SiO2)
Banded Calcite (Honey Calcite)
Calcium Carbonate (CaCO3)
Chalcedony (Variety: Agate)
Silicon Dioxide (SiO2)
Quartzite Pebble
Metamorphic Quartzite (SiO2)
Chert (with Quartz Druzy)
Microcrystalline Silica (SiO2)
Chert (Jasper influence)
Microcrystalline Quartz (SiO2)
Quartzite with Iron Inclusions
Metamorphosed Quartz-rich Rock (SiO2 with Fe2O3)