Hematite
Hematite (Iron(III) oxide, Fe2O3)
Category
Browse mineral precipitate (anthropogenic context) specimens identified by the Rock Identifier community.
Hematite
Hematite (Iron(III) oxide, Fe2O3)
Yellow Chalcedony
Silicon Dioxide (SiO2)
Limonite (Ironstone)
Limonite (FeO(OH)·nH2O)
Bumblebee Jasper (technically a type of Agate/Anhydrite)
Calcite and Anhydrite with inclusions of Realgar and Orpiment (As2S3)
Limonite (Iron-rich Siltstone / Sandstone base)
Hydrous ferric oxide mixture (FeO(OH)·nH2O)
Quartz Vein in Host Rock
Silicon Dioxide (SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Aragonite
Aragonite (CaCO3)
Chert (often called Flint in this context)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Magnetite with Pyrite or Chalcopyrite inclusions
Magnetite (Fe3O4) with Pyrite (FeS2)
Epidote and Quartz in Basalt
Epidote [Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)] in Metabasalt
Fluorite (specifically Blue John or Banded Fluorite)
Calcium Fluoride (CaF2)
Milky Quartz Vein with Matrix
Silicon Dioxide (SiO2)
Ocean Jasper
Orbicular Jasper (SiO2)
Carnelian Agate
Carnelian (Silicon Dioxide - SiO2)
River Chalcedony / Agate
Chalcedony (Silicon Dioxide, SiO2)
Milky Quartz
Quartz (Silicon Dioxide, SiO2)
Quartzite
Quartzite (primarily SiO2)
Hematite
Iron(III) oxide (Fe2O3)
Orange Calcite
Calcium Carbonate (CaCO3)
Heulandite with Stilbite
Heulandite-Ca ((Ca,Na)2-3Al3(Al,Si)2Si13O36·12H2O) and Stilbite-Ca (NaCa4(Si27Al9)O72·28H2O)
Yellow Aventurine
Quartz variety (SiO2) with inclusions
Quartz (Milky/Crystalline variety)
Silicon Dioxide (SiO2)
Orange Calcite
Calcium Carbonate (CaCO3)
Amethyst Geode
Amethyst (Silicon Dioxide, SiO2)
Hematite
Iron(III) oxide (Fe2O3)
Honey Calcite
Calcium Carbonate (CaCO3)
Quartz (Milky/Bull Quartz)
Silicon Dioxide (SiO2)
Carnelian (Chalcedony)
Silicon Dioxide (SiO2)
Milky Quartz Vein Rock
Silicon Dioxide (SiO2)
Geode (unopened) or Calcareous Nodule
Siliceous or Calcareous Concretion/Nodule
Druzy Quartz
Silicon Dioxide (SiO2)
Amethyst (Quartz)
Silicon Dioxide (SiO2) with Iron impurities
Obsidian Arrowhead
Volcanic Glass (Primary composition: SiO2)
Moqui Marble (Concretion)
Iron Oxide Concretion
Amethyst
Amethyst (Silicon Dioxide - SiO2 with Iron impurities)
Carnelian (a variety of Chalcedony)
SiO2 (Silicon Dioxide) primarily colored by iron oxide (Hematite)
Orange Calcite (Polished Sphere)
Calcium Carbonate (CaCO3)
Quartz Vein Rock
Quartz (Silicon Dioxide, SiO2)
Unidentifiable Rock Fragment
Milky Quartz
Crystalline Silicon Dioxide (SiO2)
Quartz (Druzy) in host rock
SiO₂ (Silicon Dioxide) as Quartz, with unspecified host rock components (likely silicates and iron oxides)