Septarian Nodule (Thunder Egg)
Septarian Concretion (CaCO3 + CaMg(CO3)2 + SiO2)
Category
Browse limestone specimens identified by the Rock Identifier community.
Septarian Nodule (Thunder Egg)
Septarian Concretion (CaCO3 + CaMg(CO3)2 + SiO2)
Chert (specifically a nodule with Chalcendony/Agate banding)
Microcrystalline Quartz (SiO2)
Chert (and Jasper/Flint variant)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Nodule)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (White-Grey variety)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Chert (Quartz Variety)
Chert (mostly SiO2 / Silicon Dioxide)
Chert (and Flint)
Silicon Dioxide (SiO2)
Chert Nodules (Jasper)
Microcrystalline Quartz (SiO2)
Septarian Nodule (Dragon Stone)
Septarian concretion (Complex of Calcite, Aragonite, and Limestone/Clay)
Fossiliferous Limestone (Crinoid stem)
CaCO3 (Calcium Carbonate) with Fossil Inclusions
Ammonite Fossil (Polished Section)
Ammonoidea (typically mineralized with Calcite CaCO3)
Chalk (Calcitic)
Calcium Carbonate (CaCO3) - Biogenic Sedimentary Rock
Limestone (likely Tufa or Travertine)
Calcium Carbonate (CaCO3)
Chalk
CaCO3 (primarily Calcium Carbonate), biogenic sedimentary rock
Chert (variously Flint or Jasper gravel)
Microcrystalline or cryptocrystalline Quartz (SiO2)
Zebra Marble
Recrystallized Calcite (CaCO3) with Carbonaceous Impurities
Chert (Nodule)
Chert (Alpha-Quartz, SiO2)
Chert (variations include Flint)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Orthoceras Fossil in Limestone
Orthoceras (extinct genus of cephalopods) in Carboniferous or Devonian Limestone
Honey Calcite Geode Segment
Calcite (Calcium Carbonate, CaCO3)
Fossilized Coral
Scleractinian Anthozoa (Fossilized Calcium Carbonate, CaCO3)
Chert (Flint)
Silicon Dioxide (SiO2)
Oolitic Chert
Silicon Dioxide (SiO2) with oolitic texture
Banded Chert (Jasper) River Pebble
Microcrystalline Quartz (SiO2)
Blue Calcite
Calcium Carbonate (CaCO3)
Travertine
Terrestrial Sedimentary Form of Calcium Carbonate (CaCO3)
Multi-gemstone Quartz and Fluorite Bracelet
Silicon Dioxide (SiO2) and Calcium Fluoride (CaF2)
Chert (Jasper)
Microcrystalline Quartz (SiO2)
Ruby
Corundum (Al2O3 with Chromium traces)
Chert (Greenish-Grey variety)
Microcrystalline quartz (SiO2)
Travertine
Calcareous Tufa (CaCO3)
Chert (often called Flint in archaeological contexts)
Silicon Dioxide (SiO2)
Crushed Stone / Gravel
Aggregatus saxum (variable mineral composition)
Chert (Yellow Jasper/Flint)
Silicon Dioxide (SiO2)
Chert (Flint)
Chert (Silicon Dioxide, SiO2)
Chert (White Chert/Flint)
Chert (Microcrystalline or Cryptocrystalline Quartz, SiO2)
Chert (Flint Nodules)
Chert (Microcrystalline Quartz, SiO2)
Geode (Unbroken)
Silicon Dioxide (SiO2) usually as Microcrystalline Quartz or Chalcedony
Chert (Jasper nodule)
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Jasper or Banded Chert
Silicon dioxide (SiO2) with impurities
Rainbow Fluorite
Calcium Fluoride (CaF2)
Chert (Jasper variety)
Silicon Dioxide (SiO2)