Botryoidal Goethite
Goethite (α-Fe3+O(OH))
mineral
Category
Sedimentary (Processed Mineral Product)
Browse sedimentary (processed mineral product) specimens identified by the Rock Identifier community.
Porphyritic Basalt (with Quartz or Calcite inclusion)
Porphyritic Basalt (Matrix: SiO2/MgO/FeO, Phenocryst: likely Quartz or Calcite)
igneous
Tiger's Eye
Pseudomorph of Quartz after Crocidolite (SiO2 with iron inclusions)
metamorphic
Limonite (Iron Ore)
Limonite (FeO(OH)·nH2O)
mineral
Satin Spar (Gypsum)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
mineral
Satin Spar (Gypsum)
Calcium Sulfate Dihydrate (CaSO4·2H2O)
mineral
Pyrite
Iron Sulfide (FeS2)
mineral
Moss Agate
SiO2 (Silicon Dioxide) with dendritic inclusions
Mineral
Gold Nugget
Native Gold (Au)
mineral
Limonite (Ironstone)
Hydrated Iron Oxide (FeO(OH)·nH2O)
mineral
Tiger's Eye (Rough)
SiO2 (Silicon Dioxide / Pseudomorph of Quartz after Crocidolite)
Mineral / Metamorphic
Sandstone (Banded)
Clastic Sedimentary Rock: Arenite
sedimentary
Blue Howlite (Dyed)
Calcium Borosilicate Hydroxide (Ca2B5SiO9(OH)5)
mineral
Zirconia (Ceramic) & Ion-X Glass
Zirconium Dioxide (ZrO2) and Ion-strengthened Aluminosilicate Glass
Synthetic Mineral / Glass
Quartz Geode Fragment
Silicon Dioxide (SiO2)
mineral
Shale with Siltstone layering
Sedimentary Clastic Rock (Mudstone/Shale)
sedimentary
Gneiss
Gneiss
metamorphic
Pyrite
Iron Sulfide (FeS2)
mineral
Satin Spar Selenite
Gypsum (Calcium Sulfate Dihydrate) - CaSO4·2H2O
mineral
Serpentinite
Serpentinite (composed primarily of minerals in the Serpentine group: Chrysotile, Lizardite, and Antigorite)
metamorphic
Serpentinite
Serpentinite
metamorphic
Sandstone (with Limonite staining)
Arenite (primarily SiO2 with FeO(OH)·nH2O)
sedimentary
Red Jasper
Jasper (a variety of Chalcedony, SiO₂ with iron oxide inclusions)
Mineral
Schist
Mica Schist (primarily Muscovite and Quartz)
metamorphic
Sandstone with Secondary Mineral Encrustation
Arenite with Silica/Calcite deposits (SiO2 or CaCO3)
sedimentary
Sandstone
Sandstone (composed primarily of sand-sized minerals or rock grains)
sedimentary
Transit Token (RTD Denver)
Nickel-plated brass or bronze alloy (Cu-Sn-Zn-Ni)
not a rock or mineral (anthropogenic material)
Sandstone (likely with Quartz Veining)
Arenite (primarily SiO2)
sedimentary
Blue Quartzite
Quartzite with inclusions (often Dumortierite or Magnesio-riebeckite), SiO2
metamorphic
Schist
Mica Schist (primarily Muscovite and Quartz)
metamorphic
Blue Tiger's Eye (Hawk's Eye)
Silicified Crocidolite (Pseudomorph of Quartz after Crocidolite), SiO2
metamorphic
Tiger's Eye
Pseudomorph of quartz after crocidolite (SiO2 with iron inclusions)
metamorphic
Mica Schist
Mica Schist (primarily Muscovite and Biotite phyllosilicates)
metamorphic
Quartz / Quartzite
Silicon Dioxide (SiO2)
Mineral / Metamorphic
Sandstone (likely Quartzose Sandstone)
Arenite (primarily SiO2)
sedimentary
River Cobble (likely Basalt or Rhyolite)
Extrusive Igneous Rock (Mafic or Intermediate)
igneous
Sandstone or Mudstone with Iron Staining
Ferruginous Sandstone/Mudstone
Sedimentary
Serpentine
Serpentinite (a rock composed primarily of serpentine minerals like antigorite, chrysotile, and lizardite; general formula (Mg, Fe)3Si2O5(OH)4)
metamorphic
Fish Fossil in Limestone
Lycoptera (likely) in Micritic Limestone
sedimentary
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Rhodonite
Manganese Silicate (Mn,Fe,Mg,Ca)SiO3
mineral
Aragonite (Yellow/Honey Tumble)
Calcium Carbonate (CaCO3)
mineral