Sedimentary (Silicified Fossiliferous Chalcedony)

Petrified Wood

Silicified Wood (primarily SiO2)

Mixed pebble collection, including likely flint, quartzite, and fossil material

Varied silicate rocks; visible specimen may include chert (microcrystalline SiO₂), quartzite, and a possible fossil

Fossiliferous Limestone with Brachiopod

Phylum Brachiopoda in calcitic matrix

Chert (and Fossiliferous Limestone)

Silicon Dioxide (SiO2) within Calcium Carbonate (CaCO3)

Quartz-rich weathered rock, possibly quartzite

Quartzite (mostly SiO₂); exact identification is uncertain from the image

Weathered breccia or hydrothermal vein rock

Silicified polymict breccia, likely quartz–iron-oxide breccia

Tumbled limestone pebble

Micritic limestone, chiefly calcite (CaCO₃)

Sandstone

Arenite (SiO2 primarily)

Limestone

Limestone (Calcium Carbonate - CaCO3)

Sandstone

Arenite (typically SiO2 + others)

Limestone Breccia

Sedimentary Breccia (Calcareous)

Fossil Sponge / Horn Coral / Crinoid Stem

Phylum Porifera or Cnidaria fossilized in calcium carbonate / silica

Brachiopod Fossil

Phylum Brachiopoda (order potentially Spiriferida)

Weathered limestone fragment

Limestone, predominantly calcite (CaCO₃)

Fossil Coral and Quartz Pebble

Fossilized Anthozoa / Silicon Dioxide (Quartz)

Polished orbicular jasper (likely ocean jasper)

Silicified microcrystalline quartz/chalcedony; SiO₂, with iron-oxide inclusions

Fossilized Coral (Favosites)

Favosites goldfussi / Tabulata

Petrified Wood

Silicified Wood (primarily SiO2)

Petrified Wood

Silicified Wood (primarily SiO2)

Petrified Wood

Silicified wood (Quartz, SiO2)

Fossiliferous limestone pebble

Bioclastic limestone, chiefly calcite (CaCO₃), possibly containing small fossil fragments

Polished orbicular jasper (likely ocean jasper)

Silicified volcanic rock; predominantly microcrystalline quartz/chalcedony (SiO₂) with iron oxides and possible feldspar/zeolite inclusions

Limestone with Quartz/Calcite Veins

Sedimentary Limestone (CaCO3 with SiO2 or CaCO3 intrusions)

Petrified Wood

Silicified wood (Quartz, SiO2)

Weathered limestone

Limestone, predominantly calcite (CaCO₃)

Stromatolite fossil in Chert/Jasper

Cyanobacteria / Microcystis (fossilized)

Fossiliferous Limestone with Brachiopods

Calcium Carbonate (CaCO3) with fossilized Brachiopoda sp. (likely Order Spiriferida or Rhynchonellida)

Weathered limestone

Micritic to fossiliferous limestone; primarily calcite (CaCO₃)

Fossil Coral (Favosites)

Favosites (Order: Tabulata, Phylum: Cnidaria)

Orbicular jasper (likely brecciated jasper)

Microcrystalline quartz/chalcedony (SiO₂) with iron-oxide and silica-rich clasts

Fossiliferous shale or mudstone with a brachiopod fossil

Likely a spiriferid brachiopod fossil in dark shale/mudstone; exact species and age require locality and examination

Quartz-rich chalcedony (likely agate or jasper)

Microcrystalline quartz, SiO₂; possibly a quartzite or silicified rock

Fossiliferous Limestone / Coral Fossil

Fossiliferous Limestone with Anthozoa (Coral) fossil

Chert (and Fossilized Brachiopod shell)

Sedimentary Cryptocrystalline Quartz (SiO2)

Weathered limestone

Calcitic limestone, primarily CaCO₃ (often recrystallized toward marble)

Fossilized Pycnodonte Oyster

Pycnodonte (Gryphaeostrea) species; Composition is Calcium Carbonate (Calcite/Aragonite)

Sandstone or Mudstone

Sedimentary Rock

Fossiliferous limestone fragment

Calcitic limestone; mainly calcium carbonate (CaCO₃), possibly with shell or coral debris

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Fossilized Brachiopod

Phylum Brachiopoda (Calcium Carbonate/Silica replacement)

Rounded river cobble, likely weathered sandstone or siltstone

Quartz-rich clastic sedimentary rock; exact identification requires a fresh surface and testing

Tumbled fossiliferous limestone

Calcite-rich limestone (CaCO₃), possibly fossiliferous micrite