Sandstone with Iron Staining
Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)
Category
Browse organic gemstone (sedimentary associations) specimens identified by the Rock Identifier community.
Sandstone with Iron Staining
Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)
Fossiliferous Limestone
Biogenic Limestone (Calcium Carbonate, CaCO3)
Chert (River Cobble)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Banded Chert
Microcrystalline Quartz (SiO2)
Chert (specifically Gray/Tan Chert Node)
Microcrystalline Quartz (SiO2)
Chert (Yellow/Tan Variety)
Chert (SiO2)
Ammonite Fossil (Small Pyritized or Calcitized Internal Mold)
Ammonoidea
Chert (often called Flint or Jasper when pigmented)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (specifically a nodule with Chalcendony/Agate banding)
Microcrystalline Quartz (SiO2)
Limestone (specifically fossiliferous/skeletal limestone)
Calcium Carbonate (CaCO3)
Shale with Vein Infillings
Shale (a fine-grained clastic sedimentary rock). The veins could be Calcite (CaCO3), Quartz (SiO2), or other minerals.
Banded Jasper (Chert)
Silicon Dioxide (SiO2) - variety of Chalcedony
Mother of Pearl (Nacre)
Calcium Carbonate (primarily aragonite, with conchiolin)
Amber
Succinite (specifically for Baltic amber); chemical formula approx. C10H16O
Shale (possibly Carbonaceous or Oil Shale)
Laminated Mudstone (primarily clay minerals and quartz)
Petrified Wood
Silicified Wood (primarily SiO2)
Green Moss Agate
Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite
Labradorite (likely Black Labradorite or Larvikite)
Labradorite (Na,Ca)(Al,Si)4O8. If a rock, it is typically anorthosite, gabbro, or norite, or a variety of syenite called Larvikite if it is specifically from Larvik, Norway.
Calcareous Tufa / Limestone Fragment
Calcium Carbonate (CaCO3)
Ironstone Concretion (Ironstone Gourd)
Limonite/Goethite Concretion (FeOO(H))
Amber
Succinicum (Succinite); C10H16O
Dragon Stone
Ohko Stone (Argillaceous sedimentary rock)
Gastropod Fossil (Internal Mold)
Phylum Mollusca, Class Gastropoda (Steinkern)
Crinoid Fossil in Limestone
Crinoid (Class Crinoidea) in Fossiliferous Limestone (CaCO3)
Chert (and Petrified Wood)
Silicon Dioxide (SiO2)
Chert with Druzy Quartz Geode
Microcrystalline Quartz (SiO2)
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Chert Pebble (Flint)
Microcrystalline/Cryptocrystalline Quartz (SiO2)
Limonite-stained Chert
Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)
Petrified Wood
Silicified wood (Quartz variant, SiO2)
Chert / River Jasper
Microcrystalline Quartz (SiO2)
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (variations include Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (Septarian or Nodular variety)
Microcrystalline Quartz (SiO2)
Dendritic Agate / Moss Agate
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Chert (Chalcedony/Agate)
Microcrystalline Quartz (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Fossiliferous Limestone
Calcium Carbonate (CaCO3) with Biogenic Inclusions
Chert (Jasper/Flint variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)