Ironstone Concretion
Siderite or Hematite Concretion
Category
Browse organic (anthropogenic) specimens identified by the Rock Identifier community.
Ironstone Concretion
Siderite or Hematite Concretion
Fossil Coral (Rugose Coral Fragment)
Rugosa (extinct order of solitary and colonial corals)
Petrified Wood
Silicified Wood (SiO2)
Fossiliferous Limestone (Coquina)
Biogenic Limestone (Calcium Carbonate, CaCO3)
Turquoise and Spiny Oyster (Heishi style beads)
Turquoise (CuAl6(PO4)4(OH)8·4H2O) and Spondylus (Spiny Oyster shell)
Chert (River Pebble)
Chert (Microcrystalline Quartz, SiO2)
Chert (and Flint)
Silicon dioxide (SiO2) - Microcrystalline quartz
Chert (Nodular)
Microcrystalline Silica (SiO2)
Chert (Flint/Chalcedony)
Microcrystalline Quartz (SiO2)
Fossiliferous Limestone (Coquina / Shell Limestone)
CaCO3 (Calcium Carbonate)
Chert (often called Flint or Jasper)
Microcrystalline or Cryptocrystalline Silicon Dioxide (SiO2)
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Fossiliferous Limestone
Calcite (CaCO3) with Bioclastic inclusions
Chert (often called Jasper in this color variety)
Microcrystalline Quartz (SiO2)
Chert (specifically Flint or Jasper variant)
Silicon Dioxide (SiO2)
Jasper
Silicon dioxide (SiO2)
Chert (Chalcedony)
Silicon Dioxide (SiO2)
Chert (specifically Gray Chert)
Chert (SiO2)
Septarian Nodule
Septarian Concretion (CaCO3 with Siderite/Limonite streaks)
Chert (Pink Chert / Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (specifically Black Chert or Flint)
Cryptocrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Chert (specifically Jasper/Brown Chert)
Silicon Dioxide (SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Turquoise, Pearl, and Coral Necklace
CuAl6(PO4)4(OH)8·4H2O (Turquoise) / CaCO3 (Pearl and Coral)
Chert (White Chert)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint Pebble)
Microcrystalline quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Chalcedony)
Microcrystalline Quartz (SiO2)
Chert (Iron-stained)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert / Flint
Microcrystalline or cryptocrystalline quartz (SiO2)
Green Chert
Microcrystalline Quartz (SiO2)
Jasper
Silicon Dioxide (SiO2) with iron oxide impurities
Chert (Flint)
Microcrystalline Quartz (SiO2)
Jasper
Silicon dioxide (SiO2)
Chert / River Pebble
Silicon Dioxide (SiO2)
Chert (Jasper/Agate variety)
Microcrystalline quartz (SiO2)
Chert (variations include Flint or Jasper)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Chert (Tan or Buffer variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)