Ammonite Fossil
Ammonoidea
Category
Browse sedimentary (with some aspects of mineral replacement) specimens identified by the Rock Identifier community.
Ammonite Fossil
Ammonoidea
Stromatolite
Biogenic sedimentary structure (Stromatolite)
Fossil Shark Tooth
Chondrichthyes (class)
Galena
Lead Sulfide (PbS)
Chert with Druzy Quartz Geode
Microcrystalline Quartz (SiO2)
Red Jasper
Jasper (Silicon Dioxide with iron oxide inclusions), SiO2
Milky Quartz
Silicon Dioxide (SiO2)
Jasper (Red-Brown)
Silicon Dioxide (SiO2) with Iron Oxide impurities
Petrified Wood
Silicified Wood (SiO2)
Chert (Jasper variation)
Microcrystalline Quartz (SiO2)
Limonite-pseudomorph after Pyrite (Prophecy Stone)
Goethite and Limonite secondary minerals (FeO(OH)·nH2O) replacing Pyrite (FeS2)
Chert
Microcrystalline Quartz (SiO2)
Jasper
Jasper (Silicified microcrystalline quartz) - SiO2
Fossil Shark Tooth
Chondrichthyes dentition (Fossilized Tooth)
Flint
Chert (SiO2)
Fossilized Shell
Invertebrate fossil (Bivalvia or Brachiopoda)
Chert (Agate/Flint variant)
Microcrystalline Quartz (SiO2)
Chert
Microcrystalline Quartz (SiO2)
Fossil Snail
Gastropoda (fossilized)
Chert / Flint
Cryptocrystalline Quartz (SiO2)
Chert (often called Flint when dark)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Jasper/Flint variety)
Microcrystalline Quartz (SiO2)
Petrified Wood
Silicified Wood (primarily Quartz/Chalcedony, formula SiO2)
Chert (Field Stone)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Chert (Field-collected variety)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Crinoid Stem Fossil
Crinoid columnal (Echinodermata)
Fossilized Shark Tooth
Chondrichthyes (Class)
Fossil Shell (Bivalve)
Class Bivalvia (fossilized)
Chert (Flint)
Chert (SiO2)
Galena (likely)
Galena, lead sulfide (PbS)
Echinoid Fossil (Sea Urchin)
Echinoidea (specifically likely Schizaster or similar genus), calcium carbonate (CaCO3)
Fossilized Echinoid / Sea Urchin Internal Mold
Echinoidea internal cast (steinkern)
Fossilized Coral
Rugosa / Scleractinia (Agatized or Calcitized Coral)
Chert (Flint)
Microcrystalline Quartz (SiO2)
Galena
Lead sulfide (PbS)
Rodonite
Rhodonite (MnSiO3)
Chert (Flint Nodules)
Microcrystalline or Cryptocrystalline Quartz (SiO2)
Ocean Jasper
Orbicular Jasper (variety of Chalcedony - SiO2)
Petrified Wood (Silicified Wood)
Silicified Wood / Silicon Dioxide (SiO2)
Petrified Wood (Agatized/Silicified Wood)
Silicified Wood (SiO2 - Silicon Dioxide)
Petrified Wood
Silicified Wood (SiO2 - primarily Quartz/Chalcedony/Opal)
Magnetite-rich Iron Ore
Magnetite (Fe3O4)