Travertine
Terrestrial Sedimentary Limestone (CaCO3)
Category
Browse organic (often found by beachcombers) specimens identified by the Rock Identifier community.
Travertine
Terrestrial Sedimentary Limestone (CaCO3)
Chert (with Limestone matrix)
Silicon dioxide (SiO2)
Chert / Flint
Silicon Dioxide (SiO2)
Red Jasper
Jasper (Silicon Dioxide, SiO2)
Chert (often called Flint or Jasper)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Amber
Succinicum (C10H16O)
Shale
Mudstone (composed primarily of clay minerals like kaolinite, illite, and smectite, with quartz and calcite)
Pyrite
Iron Sulfide (FeS2)
Chert (Holey Stone)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily SiO2)
Chert (Flint)
Silicon Dioxide (SiO2)
Jasper
Silicon dioxide (SiO2) with impurities
Coal (likely Bituminous or Lignite)
Organic Sedimentary Rock (Carbonaceous)
Fossil Shark Tooth
Carcharodon or Carcharias fossil (Vertebrate Fossil)
Banded Chert
Microcrystalline Quartz (SiO2)
Red Jasper
Silicon Dioxide (SiO2) with Iron inclusions
Jasper
Silicon Dioxide (SiO2)
Petrified Wood
Silicified Wood (SiO2)
Travertine (Tufa)
Chemical Limestone (CaCO3)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Chalk
Calcium Carbonate (CaCO3)
Chert (variations include Flint)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Flint/Jasper)
Silicon dioxide (SiO2) - Microcrystalline quartz
Chert (Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Sea Glass (Cobalt Blue)
Amorphous Silica (Glass with Cobalt additives)
Petrified Wood
Silicified Wood (SiO2 - Silicon Dioxide)
Fossil Shark Tooth
Otodus sp. (likely Otodus obliquus) fossil
Chert (Jasper)
Microcrystalline Silica (SiO2)
Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
Chert (often called Flint for dark variants)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Yellow Jasper variant)
Microcrystalline Quartz (SiO2)
Chert Fossil (Pebble)
Microcrystalline Quartz (SiO2) with biogenic inclusions
Chert (Flint)
Microcrystalline Quartz (SiO2)
Chert (Flint)
Cryptocrystalline Quartz (SiO2)
Green Jasper
Silicon Dioxide (SiO2) with impurities of iron(II) silicate
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Greenstone / Chert
Cryptocrystalline Quartz (SiO2) or Altered Basalt
Chert (Yellow Jasper variant)
Microcrystalline quartz (SiO2)
Chert (Jasper)
Cryptocrystalline Quartz (SiO2)
Jasper
Jasper (Silicon Dioxide, SiO2)
Graphite
Graphite (C)