Dendritic Agate / Moss Agate
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Category
Browse organic (biological specimen) specimens identified by the Rock Identifier community.
Dendritic Agate / Moss Agate
Silicon Dioxide (SiO2) with Manganese/Iron oxide inclusions
Sandstone with Trace Fossils
Quartz Arenite with Bioturbation (Trace Fossils)
Baltic Amber
Succinite (Fossilized Resin)
Chert (with Quartz veins)
Chert (Microcrystalline Silicon Dioxide, SiO2)
Chert (Jasper/Flint variety)
Microcrystalline quartz (SiO2)
Petrified Wood
Silicified wood (Quartz replacement)
Chert (often called Flint when dark)
Chert (Microcrystalline or Cryptocrystalline Silica, SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Tufa
Calcareous Tufa (Calcium Carbonate, CaCO3)
Chert (Flint)
Cryptocrystalline quartz (SiO2)
Pink Opal
Hydrated Silicon Dioxide (SiO2 · nH2O)
Coal
Bituminous coal (Complex organic sedimentary rock)
Petrified Wood
Silicified Wood (primarily SiO2)
Precious Coral
Corallium rubrum (Calcium Carbonate, CaCO3)
Moss Agate
Silicon Dioxide (SiO2) with inclusions of hornblende or chlorite
Amber Inlay Jewelry
Fossilized Resin (C10H16O)
Chert (variations include Flint/Jasper)
Cryptocrystalline Quartz (SiO2)
Fossilized Shark Tooth
Chondrichthyes (Class)
Red Sandstone
Arenite (Iron-rich Sandstone)
Coquina Limestone (Fossiliferous Limestone)
Calcareous bioclastic sedimentary rock (CaCO3)
Chert (specifically Jasper or Flint type)
Microcrystalline Quartz (SiO2)
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Yellow Chert (Jasper)
Microcrystalline Quartz (SiO2)
Fancy Jasper
Silicon dioxide (SiO2)
Red Chert (Jasper)
Silicon Dioxide (SiO2)
Limonite-stained Chert
Silicon Dioxide (SiO2) with Hydrated Iron Oxide (FeO(OH)·nH2O)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chert (Flint variety)
Chert (Microcrystalline or Cryptocrystalline Quartz), SiO2
Sandstone Pebble (River Rock)
Sandstone (Quartz-rich sedimentary rock with iron oxide staining)
Glauconitic Sandstone (Greensand)
Glauconitic Sandstone ((K, Na)(Fe3+, Al, Mg)2(Si, Al)4O10(OH)2)
Petrified Wood
Silicified Wood (primarily SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Pearl
Organic gemstone (Calcium carbonate / CaCO3 + Conchiolin)
Sandstone (likely Fossilized Wood or Concrete Simulacrum)
Arenite / Silicified Wood / Anthropogenic Concrete
Petoskey Stone
Hexagonaria percarinata (Fossilized Rugose Coral)
Black Pearl (Tahitian or Irradiated Type)
Organic gemstone (Calcium Carbonate with Conchiolin Binding)
Precious Coral
Corallium rubrum (Calcium carbonate with trace carotene)
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Chert (Nodule)
Silicon Dioxide (SiO2)
Chert / River Jasper
Microcrystalline Quartz (SiO2)
Tumbled amber-like inclusion
Likely amber (fossilized tree resin; complex polymer), but identification is uncertain from the image
Jasper (Green Jasper / Chert)
Silicon Dioxide (SiO2 with inclusions)