Hematite
Iron(III) oxide (Fe2O3)
Category
Browse sedimentary (secondary classification for a weathered mineral specimen) specimens identified by the Rock Identifier community.
Hematite
Iron(III) oxide (Fe2O3)
Chert / Chalcedony
Silicon Dioxide (SiO2)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Geodal Limestone / Calcite Druze
Calcium Carbonate (CaCO3)
Yellow Jasper
Silicon Dioxide (SiO2) with hydrated iron oxide impurities
Ferruginous Sandstone (Ironstone)
Clastic Sedimentary Rock (composed of SiO2 with Fe2O3/FeO(OH) cement)
Sandstone (Quartzite-rich)
Clastic sedimentary rock (SiO2 primary)
Chert (Agatized Chert)
Microcrystalline Quartz (SiO2)
Olivine (Peridot when gem-quality)
Olivine Group (Magnesium Iron Silicate, (Mg,Fe)2SiO4)
Quartz (Grain/Fragment)
Silicon Dioxide (SiO2)
Chalcedony (Agate)
Silicon Dioxide (SiO2)
Chert (with Quartz Veining)
Microcrystalline Quartz (SiO2)
Quartz (Milky or Rough Quartz)
Silicon Dioxide (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Moqui Marble (Ironstone Concretion)
Goethite/Hematite Concretion (Fe2O3 / FeO(OH))
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
Chert (Flint variety)
Silicon Dioxide (SiO2)
Quartz (Milky or Cloudy Quartz)
Silicon Dioxide (SiO2)
Opal
Hydrated Amorphous Silica (SiO2·nH2O)
Banded Gneiss
Gneiss (High-grade regional metamorphic rock)
Pyrite in Matrix (often with Chalcopyrite)
Iron Sulfide (FeS2) / Copper Iron Sulfide (CuFeS2)
Septarian Nodule (Yellow Calcite in Limestone)
Septarian Concretion (CaCO3 with Aragonite and Calcite)
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
Agate (Grey Agate Slice)
Microcrystalline Quartz (SiO2)
Arid Sandy Loam
Arenosols / Regosols
Chert (White Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper variation)
Silicon Dioxide (SiO2)
Chert (Flint)
Cryptocrystalline Silica (SiO2)
Quartzite
Metamorphosed Quartz Sandstone (SiO2)
Stromatolite (Fossiliferous Limestone)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Banded Sandstone (Differential Weathering)
Clastic Sedimentary Rock (primarily SiO2)
Banded Gneiss (with possible weathered sulfide or iron staining)
Gneiss, potentially with iron oxide/hydroxide staining (e.g., limonite) or weathered sulfides
Red Sandstone
Arenite (Ferruginous Sandstone)
Chert (specifically Banded Chert)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Greywacke (River Slikkenstone)
Greywacke (Impure Sandstone)
Chert (Jasper variety) with Iron Oxide staining
Cryptocrystalline Quartz (SiO2) with Goethite/Limonite impurities
Quartz (Milky or White Quartz)
Silicon Dioxide (SiO2)
Diamond (Cut jewelry specimen)
Diamond (pure Carbon, C)
Fossiliferous Sandstone (with Brachiopod or Bivalve mold)
Clastic Sedimentary Rock with Macrofossil Mold
Kimberlite
Kimberlite
Pink Granite
Felsic Plutonic Rock (primarily Quartz, Potassium Feldspar, and Plagioclase)
Orange Calcite
Calcium Carbonate (CaCO3)