Agate Geode
Cryptocrystalline Quartz (SiO2)
Category
Browse sedimentary rock (technically a variety of chalcedony) specimens identified by the Rock Identifier community.
Agate Geode
Cryptocrystalline Quartz (SiO2)
Sandstone (Ferruginous)
Sandstone (primarily SiO2 with Iron Oxide cement)
Quartz Vein in Sedimentary Rock
Silicon Dioxide (SiO2) with host Chert or Limestone
Chert (Flint)
Silicon Dioxide (SiO2)
Quartz Pebble (Chalcedony/Agate)
Silicon Dioxide (SiO2)
Sandstone
Arenite (primarily SiO2)
Quartz Geode (partially opened)
Silicon Dioxide (SiO2) with iron staining
Tiger's Iron
Pseudomorphic Quartz Aggregate (contains SiO2 with Fe2O3 and FeOOH)
Sandstone
Arenite (SiO2 based)
Dalmation Stone
Peralkaline Rock (mixed silicate minerals)
Sandstone
Arenite (SiO2 primarily)
Porphyry
Porphyritic Rhyolite or Andesite
Jasper
Agate/Jasper (Microcrystalline Quartz, SiO2)
Dark Igneous Rock (Likely Basalt or Diabase)
Basalt (extrusive igneous rock) or Diabase (intrusive igneous rock - also known as Dolerite), largely composed of plagioclase feldspar, pyroxene (augite), and sometimes olivine and amphibole. Exact mineralogy would require thin section analysis.
Dyed Chalcedony (Agate)
Silicon Dioxide (SiO2) with artificial pigment
Sandstone
Arenite (SiO2 principal)
Quartz Geode
Silicon Dioxide (SiO2)
Amber (Cherry or Red variety)
Succinite (with various trace amounts of organic compounds)
Pyrite
Iron Sulfide (FeS2)
Fluorite (Blue)
Calcium Fluoride (CaF2)
Sandstone
Clastic sedimentary rock (primarily SiO2)
Sandstone (likely Arkose or Quartz Sandstone)
Clastic sedimentary rock (primarily SiO2)
Sandstone
Arenite (primarily SiO2)
Milky Quartz (among River Rock)
Quartz (Silicon Dioxide, SiO2)
Quartz Geode
Silicon Dioxide (SiO2) in Host Rock
Geode (Chert or Quartz Nodule)
Silicon Dioxide (SiO2)
Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Green Fluorite
Fluorite (Calcium Fluoride, CaF2)
Sandstone
Arenite (primarily SiO2)
Serpentinite
Serpentinite (composed primarily of minerals in the Serpentine group)
Serpentine (Serpentinite)
Antigorite, Lizardite, or Chrysotile (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4
Yellow Chalcedony (Agate/Carnelian variant)
Silicon Dioxide (SiO₂)
Chalcedony (Moonstone variant or White Agate)
Silicon Dioxide (SiO₂)
Sandstone (lithic/greywacke variant)
Clastic sedimentary rock (primarily SiO2 with rock fragments)
Sandstone (Quartzite Pebble)
Arenite (primarily SiO2)
Carnelian Agate
Chalcedony (Silicon Dioxide, SiO2) with Iron Oxide impurities
Druzy Quartz on Host Rock
Silicon Dioxide (SiO2)
Granular Sandstone
Arenite (variable composition, primarily SiO2)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Petrified Wood
Silicified Wood (primarily SiO2)
Pyrite
Iron Sulfide (FeS2)
Orange Calcite
Calcium Carbonate (CaCO3)