Amethyst
Silicon dioxide (SiO2)
mineral
Category
Sedimentary (Processed Mineral Product)
Browse sedimentary (processed mineral product) specimens identified by the Rock Identifier community.
Learn about Sedimentary (Processed Mineral Product) in the encyclopedia
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Tiger's Eye (Rough Slab)
Pseudomorph of Quartz after Crocidolite (SiO2 with Fe-containing inclusions)
mineral
Quartz Pebble
Silicon Dioxide (SiO2)
mineral
Quartz (Iron-Stained Quartz Pebble)
Silicon Dioxide (SiO2)
mineral
Specular Hematite (Specularite)
Iron Oxide (Fe2O3)
mineral
Orbicular Jasper (Ocean Jasper)
Silicon Dioxide (SiO2) with iron and magnesium inclusions
mineral
Blue Dyed Agate
Chalcedony (cryptocrystalline variety of Quartz), SiO2
mineral
Blue Agate (Dyed)
Silicon Dioxide (SiO2) - Cryptocrystalline Quartz
mineral
Yellow Calcite
Calcium Carbonate (CaCO3)
mineral
Quartz Geode
Silicon Dioxide (SiO2)
mineral
Smoky Quartz
Silicon Dioxide (SiO2)
mineral
Fluorite
Calcium Fluoride (CaF2)
mineral
Jasper or Agate
Silicon dioxide (SiO2)
Mineral
Celestine (Celestite)
Strontium sulfate (SrSO4)
mineral
Ironstone (Limonite/Hematite concretion)
Ferruginous Siltstone / Goethite (FeO(OH))
sedimentary
Transit Token (RTD Denver)
Nickel-plated brass or bronze alloy (Cu-Sn-Zn-Ni)
not a rock or mineral (anthropogenic material)
Quartz Crystal Cluster
Silicon Dioxide (SiO2)
mineral
Pyrite
Iron Disulfide (FeS2)
Mineral
Tiger's Eye (Rough)
Pseudomorph of Quartz after Crocidolite (SiO2 with iron inclusions)
metamorphic
Quartz Vein on Matrix
Silicon Dioxide (SiO2)
mineral
Red Jasper
Jasper (a variety of Chalcedony, SiO₂)
Mineraloid (cryptocrystalline quartz)
Sandstone (Ferruginous)
Arenite (Fe-oxide cemented)
sedimentary
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe)3Si2O5(OH)4)
metamorphic
Serpentinite
Serpentinite (composed largely of Serpentine minerals such as Lizardite, Antigorite, and Chrysotile: Mg3Si2O5(OH)4)
metamorphic
Mixed Mineral and Fossil Collection
Multi-specimen assemblage (SiO2, CaCO3, FeS2, etc.)
mineral
Quartz Pebble
Quartz (Silicon Dioxide, SiO2)
mineral
Verde Antique Marble (Serpentinite)
Serpentinite (composed mainly of Serpentine group minerals, Mg3Si2O5(OH)4)
metamorphic
Quartz (Druzy)
Silicon Dioxide (SiO2)
mineral
Green Quartzite (Aventurine-like)
Quartzite (primarily SiO2 with chromium-rich mica or chlorite inclusions)
metamorphic
Mica Schist
Mica Schist (Complex Silicate Rock)
metamorphic
Native Gold Nugget
Native Gold (Au)
mineral
Carborundum
Silicon Carbide (SiC)
mineral
Gneiss
Gneiss
metamorphic
Quartz Pebble
Silicon Dioxide (SiO2)
Mineral (occurring as a rolled clast)
Sandstone
Sandstone (composed primarily of sand-sized minerals or rock grains)
sedimentary
Pyrite
Iron Sulfide (FeS2)
mineral
Quartzite
Quartzite (primarily SiO2)
metamorphic
Serpentinite
Serpentinite (composed primarily of Serpentine group minerals: (Mg,Fe,Ni,Al,Zn,Mn)2-3(Si,Al,Fe)2O5(OH)4)
metamorphic
Jasper
Silicon dioxide (SiO2)
sedimentary
Sandstone (with Limonite staining)
Arenite (primarily SiO2 with FeO(OH)·nH2O)
sedimentary
Brachiopod Fossil in Limestone
Phylum Brachiopoda (likely Order Spiriferida), CaCO3 (Calcite)
sedimentary
Red Slag Glass
Amorphous Silica (Industrial byproduct with metallic oxide dopants)
Mineraloid / Industrial Byproduct