Chert (Common Opal variant)
Silicon Dioxide (SiO2)
Category
Browse sedimentary (secondary mineral formation) specimens identified by the Rock Identifier community.
Chert (Common Opal variant)
Silicon Dioxide (SiO2)
Red Sandstone
Arenite (ferruginous sandstone)
Petrified Wood
Silicified Wood (SiO2)
Fluorite
Fluorite (Calcium Fluoride - CaF2)
Limestone with Quartz/Calcite Veins
Sedimentary Limestone (CaCO3 with SiO2 or CaCO3 intrusions)
Turquoise
CuAl6(PO4)4(OH)8·4H2O (Hydrated copper and aluminum phosphate)
Milky or Iron-Stained Quartz
Quartz (Silicon Dioxide, SiO2)
Agate (specifically Lace Agate or Banded Agate)
Silicon Dioxide (SiO2)
Sandstone
Arenite (primarily SiO2)
Sandstone
Arenite (composed primarily of SiO2)
Banded Calcite (often sold as 'Mexican Onyx' or 'Calcite Onyx')
Calcite (Calcium Carbonate, CaCO3)
Sandstone
Arenite (SiO2 based)
Orange Calcite
Calcium Carbonate (CaCO3)
Rhodochrosite
Manganese carbonate (MnCO3)
Banded Agate (River Stone)
Agate (Silicon Dioxide - SiO2)
Greenstone / Chert
Cryptocrystalline Quartz (SiO2) or Altered Basalt
Fossilized Wood (with Coal and Limonite)
Petrified Wood (Silicified or Carbonized Flora)
Red Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Sandstone (Quartzose)
Arenite (composed primarily of SiO2)
Jasper with Quartz inclusions
Silicon Dioxide (SiO2) - Microcrystalline Chalcedony
Red Jasper
Silicon Dioxide (SiO2) with Hematite (Fe2O3) inclusions
Wonderstone (Sandstone)
Silicified Quartz Sandstone with Iron Oxide staining
Bloodstone / Heliotrope
Silicon dioxide (SiO2) with inclusions
Quartz Geode
Silicon Dioxide (SiO2) within a secondary sedimentary structure
Geode (unopened) or Calcareous Nodule
Siliceous or Calcareous Concretion/Nodule
Pink Stained Rock (Likely Quartzite or Sandstone with Iron Oxide Staining)
Quartzite (metamorphic) or Sandstone (sedimentary); coloration likely due to hematite or other iron oxides.
Sandstone (Ferruginous)
Arenite with Iron Oxide cement (SiO2 + Fe2O3)
Sandstone
Arenite (SiO2 primarily)
Sandstone
Arenite (composed primarily of SiO2)
Amethyst
Amethyst (Silicon Dioxide - SiO2 with iron impurities)
Travertine
Terrestrial Sedimentary Rock (CaCO3)
Sandstone
Arenite (primarily SiO2)
Jasper pebble
Silicon dioxide (SiO2) with iron oxide inclusions
Red Sandstone
Arenite (high iron oxide content)
Native Copper with Malachite and Chrysocolla
Native Copper (Cu) with Malachite [Cu2CO3(OH)2] and Chrysocolla [(Cu,Al)2H2Si2O5(OH)4·nH2O]
Sandstone
Arenite (primarily SiO2)
Quartz (Milky/Iron-stained)
Silicon Dioxide (SiO2)
Red Quartz (Carnelian/Red Jasper Agate)
Silicon Dioxide (SiO2) with Iron Oxide inclusions
Red Sandstone
Arenite (primarily Quartz with Hematite cement)
Orange Calcite
Calcium Carbonate (CaCO3)
Dyed Agate Slice
Silicon Dioxide (SiO2) with artificial colorants
Mica-rich Sandstone or Micaceous Schist Weathering
Micaceous Schist (Muscovite-Quartz composition)