Devil's Toenail (Fossil Oyster)
Gryphaea arcuata (Calcium Carbonate, CaCO3)
Category
Browse mineral (sedimentary context) specimens identified by the Rock Identifier community.
Devil's Toenail (Fossil Oyster)
Gryphaea arcuata (Calcium Carbonate, CaCO3)
Sandstone
Arenite (primarily SiO2)
Banded Jasper
Silicon Dioxide (SiO2) with iron oxide inclusions
Polychrome Jasper
Silicon Dioxide (SiO2) with iron and other mineral inclusions
Jasper (Brown Iron-Rich Variety)
Silicon Dioxide (SiO2) with Fe2O3 (Iron Oxide/Crystalline Quartz)
Yellow Jasper
Silicon Dioxide (SiO2) with iron hydroxides (Goethite/Limonite)
Jasper (likely river-worn)
Silicon Dioxide (SiO2)
Zebra Jasper
Tumbled Opaque Chalcedony (SiO2)
Fancy Jasper (Multicolor Agate/Jasper)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Limonite (Ironstone)
Limonite (Hydrated iron(III) oxide-hydroxide, FeO(OH)·nH2O)
Gneiss (specifically Banded Gneiss)
Gneiss
Hematite (Botryoidal/Kidney Ore)
Iron(III) oxide (Fe2O3)
Blue Calcite
Calcium Carbonate (CaCO3)
Turquoise
Turquoise - CuAl6(PO4)4(OH)8·4H2O (Hydrous phosphate of copper and aluminium)
Chalcedony (Agate)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Pyrite
Iron Sulfide (FeS2)
Pyrite
Iron Disulfide (FeS2)
Green Fluorite (Beaded)
Fluorite (Calcium Fluoride, CaF2)
Fluorite (Rainbow Fluorite Point)
Calcium Fluoride (CaF2)
Druzy Quartz
Silicon Dioxide (SiO2)
Hematite
Iron(III) oxide (Fe2O3)
Hematite
Iron(III) oxide (Fe2O3)
Quartz Geode in Sedimentary Matrix
Silicon Dioxide (SiO2) within a limestone/dolostone host
Green Calcite
Calcite (CaCO3)
Sandstone
Arenite (primarily SiO2)
Sandstone
Arenite (SiO2 based)
Dalmatian Stone (commonly called Dalmatian Jasper)
Peralkaline Rock (mixed Feldspar, Quartz, and Arfvedsonite)
Red Sandstone (Iron-Rich)
Arenite (Fe2O3)
Red Sandstone
Arenite (with Iron Oxide cement)
Weathered Sandstone with Algae Growth
Arenite
Sandstone
Arenite (primarily SiO2)
Chert (Green variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert Geode or Nodule
Microcrystalline Quartz (SiO2)
Ironstone Concretion (Ironstone Gourd)
Limonite/Goethite Concretion (FeOO(H))
Bloodstone (Heliotrope)
Silicon Dioxide (SiO2) with inclusions of Chlorite or Actinolite
Geode (unopened)
Chert / Chalcedony Geode (SiO2)
Jasper
Silicon dioxide (SiO2) with impurities
Fossil Shell (Bivalve)
Class Bivalvia (Likely a member of the Ostreidae or Gryphaeidae family), CaCO3
Orbicular Jasper (Eye Jasper / Kambaba-like pattern)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, SiO2)
Yellow Jasper
Jasper (Silicon Dioxide, SiO2)
Sandstone (Graywacke type)
Clastic Sedimentary Rock (Lithic Sandstone)