Sedimentary (Silicified Fossiliferous Chalcedony)

Petrified Wood

Silicified Wood (primarily SiO2)

Mookaite Jasper

Silicified Porcellanite (SiO2 with impurities)

Red Jasper (possibly Chert/Argillite)

Jasper (SiO2) with iron oxide inclusions

Fossiliferous Chert or Limestone

Sedimentary rock containing fossilized marine invertebrates (likely crinoid stems or bryozoans)

Limestone (Weathered/Silicified)

Sedimentary carbonate rock (primarily CaCO3)

Fossiliferous Limestone Pebble

Biogenic Sedimentary Rock (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Fossilized Wood / Petrified Wood

Petrified Wood (Silicified Flora)

Fossil Coral (Petoskey Stone or Favosites)

Favosites (specifically Hexagonaria percarinata if silica-replaced Michigan type)

Gastropod Steinkern (Fossilized Snail Cast)

Phylum Mollusca, Class Gastropoda (Commonly CaCO3 or SiO2 after replacement)

Likely petrified wood or silicified fossil fragment

Silicified wood; predominantly microcrystalline quartz (SiO₂)

Fossiliferous Limestone with Quartz Veining

Limestone (Calcium Carbonate, CaCO3)

Fossiliferous limestone, possibly containing a brachiopod or bivalve fossil

Calcite-rich limestone (CaCO₃), with an apparent shell impression or shell fragment

Chalcedony

Chalcedony (SiO2)

Leopard Skin Jasper

Silicon Dioxide (SiO2) with iron and manganese inclusions

Kambaba Jasper

Stromatolite (Fossilized Algae)

Fossil Coral

Scleractinia or Anthozoa (Fossilized)

Fossiliferous Sandstone Pebble (with Crinoid / Shell Impression)

Sandstone containing fossiliferous inclusions (SiO2 matrix with calcite/silica cast fossil)

Petrified Wood

Silicified Wood (primarily SiO2)

Fossiliferous Limestone (Gastropod / Crinoid Fossil Rock)

Biogenic Sedimentary Rock (CaCO3)

Flint / Chert (Fossiliferous)

Silicon dioxide (SiO2) with microcrystalline quartz

Limestone with fossiliferous textures

Bioclastic Limestone (CaCO3)

Coquina or Fossiliferous Conglomerate

Bioclastic Rudstone (variable composition)

Chert (and Fossiliferous Chert)

Silicon Dioxide (SiO2)

Chert (or Fossiliferous Limestone)

Microcrystalline Quartz (SiO2) / Calcium Carbonate (CaCO3)

Fossiliferous Limestone with Rugose Coral

Calcite (CaCO3) matrix containing Rugosa (order of extinct solitary and colonial corals)

Limestone (fossiliferous or weathered)

Sedimentary carbonate rock primarily composed of calcium carbonate (CaCO3)

Fossiliferous limestone (likely ammonite/gastropod-bearing)

Bioclastic limestone; predominantly calcite (CaCO₃)

Fossiliferous Flint or Chert with Bryozoan Fossils

Sedimentary cryptocrystalline quartz (SiO2) with fossil inclusions

Weathered fossiliferous limestone or fossil fragment

Indeterminate bioclastic carbonate rock; likely calcite (CaCO₃) with fossil shell material

Petrified Wood

Silicified Wood (primarily SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)

Fossiliferous limestone, possibly an oyster or other bivalve fossil

Calcite (CaCO₃) shell material preserved in micritic limestone; exact fossil taxon cannot be confirmed from one image

Fossil Coral (Rugose Coral Fragment)

Rugosa (extinct order of solitary and colonial corals)

Fossiliferous Limestone / Petrifaction

Sedimentary rock with fossil inclusions / Calcium Carbonate (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Weathered carbonate rock, possibly fossiliferous limestone

Calcite-rich limestone (CaCO₃), tentative identification

Chert Fossil (Pebble)

Microcrystalline Quartz (SiO2) with biogenic inclusions

Weathered fossiliferous sandstone or mudstone cobble

Lithified siliciclastic sediment; the raised curved feature may be a trace fossil or shell impression

Fossiliferous Sandstone with Plant Remains

Arenite with Carbonaceous impressions (likely Paleozoic/Mesozoic Flora)

Chert (potentially Fossiliferous or Jasperoid)

Microcrystalline Quartz (SiO2)

Fossilized Solitary Rugose Coral (Horn Coral)

Order: Rugosa (e.g., Grewingkia or Heliophyllum); composed of Calcite (CaCO3) or Silica (SiO2)