Amethyst or Smoky Quartz Geode Slice
Crystalline Silicon Dioxide (SiO2) with iron impurities
Category
Browse sedimentary (with some aspects of mineral replacement) specimens identified by the Rock Identifier community.
Amethyst or Smoky Quartz Geode Slice
Crystalline Silicon Dioxide (SiO2) with iron impurities
Pyrite in Matrix (Fool's Gold)
Iron Sulfide (FeS2)
Quartz (Clear/White)
Silicon Dioxide (SiO2)
Calcite
Calcium Carbonate (CaCO3)
Amethyst Geode
Amethyst (Silicon Dioxide), Formula: SiO2
Iron-stained Quartz (with Limonite/Hematite)
Silicon Dioxide (SiO2) with Iron Oxide inclusions (FeO(OH) or Fe2O3)
Limestone (Concretionary or Tufa)
Calcium Carbonate (CaCO3)
Limonite (Iron Ore/Sandstone mixture)
Limonite (FeO(OH)·nH2O) often mixed with Goethite and sedimentary matrix
Hematite
Iron(III) oxide (Fe2O3)
Quartz Geode
Silicon Dioxide (SiO2)
Chalcedony (Agate/Quartz pebble)
Silicon dioxide (SiO2) - Microcrystalline Quartz
Blue Calcite
Calcium Carbonate (CaCO3)
Pyrite (on Quartz matrix)
Iron Disulfide (FeS2)
Gold Nugget
Native Gold (Au)
Calcite
Calcium Carbonate (CaCO3)
Quartz Geode
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Pyrite
Iron Sulfide (FeS2)
Milky Quartz
Silicon Dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Quartz Geode
Silicon Dioxide (SiO2)
Pyrite
Iron Sulfide (FeS2)
Adventurine (Green)
Silicon Dioxide (SiO2) with inclusions of Fuchsite
Fluorite (Green Fluorite)
Calcium Fluoride (CaF2)
Dyed Quartz Geode
Silicon Dioxide (SiO2) with artificial pigment
Agate (Carnelian / Chalcedony)
Silicon Dioxide (SiO2)
Pyrite (Fool's Gold)
Iron Sulfide (FeS2)
Sandstone with Magnetite and Iron Staining
Clastic Sedimentary Rock (contains Fe3O4 and Limonite/Hematite)
Sandstone (Micaceous)
Arenite (composed primarily of SiO2)
Limonite
Limonite (Hydrated iron(III) oxide-hydroxide) FeO(OH)·nH2O
White Quartz (Milky Quartz)
Silicon Dioxide (SiO2)
Quartz
Silicon Dioxide (SiO2)
Sandstone (Ferruginous)
Arenite (primarily SiO2 with Fe2O3 inclusions)
Quartz Geode (Cracked Open Fragment)
Silicon Dioxide (SiO2)
Limonite (also known as Yellow Ochre or Brown Hematite)
Limonite (Hydrated iron oxide-hydroxide, FeO(OH)·nH2O)
Shale
Laminated Mudstone
Sandstone (Ferruginous)
Sandstone (primarily SiO2 with Iron Oxide cement)
Limonite Concretion (Ironstone)
Limonite (FeO(OH)·nH2O) with Goethite and Hematite
Sandstone
Clastic sedimentary rock (primarily SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Green Onyx (Banded Calcite)
Travertine (CaCO3 - Calcium Carbonate)
Sandstone Concretion
Sedimentary Concretion (SiO2 or CaCO3 cemented)