Sedimentary (Base), Then Artificial

Pebble

Lithified rock fragment / Sedimentary clast

Iron-stained Quartz

Silicon Dioxide with Limonite (SiO2 + FeO(OH)·nH2O)

Chert

Chert (SiO2)

Fossilized Shell in Limestone

Carbonate sedimentary rock with Bivalvia or Brachiopoda remains

Sandstone Cobble

Arenite (Sandstone)

Chert with Iron Inclusions

Microcrystalline Quartz (SiO2) with Hematite/Limonite

Fossilized Rugose Coral

Order Rugosa (Calcium Carbonate - CaCO3)

Graphite

Graphite (Carbon, C)

Fuchsite in Quartz

K(Al,Cr)2(AlSi3O10)(OH)2 (Muscovite with Chromium)

Sandstone (likely Siltstone)

Arenite or Siltstone (high SiO2 content)

Sandstone

Arenite (SiO2 based with cement)

Sandstone

Arenite (SiO2 primarily)

Chert

Cryptocrystalline Quartz (SiO2)

Ferruginous Sandstone (Ironstone)

Sedimentary rock with Limonite/Goethite cement

Chert (Iron-stained)

Chert (Cryptocrystalline Quartz, SiO2)

Limestone with Fossil Inclusions

Sedimentary Carbonate Rock (CaCO3)

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Limestone River Pebble

Sedimentary Calcium Carbonate (CaCO3)

Sandstone (likely with Borings or Vesicular Basalt)

Clastic Sedimentary Rock (Sandstone)

Limestone (with Iron-Oxide staining)

Sedimentary Calcium Carbonate (CaCO3)

Cone-in-cone structure (Limestone)

Cone-in-cone structure (Secondary Sedimentary Structure)

Fossil Shark Tooth

Odontaspididae (Sand Tiger Shark family)

Conglomerate

Conglomerate

Quartz-veined Siltstone

Siltstone with Quartz (SiO2) veins

Gold Mineral

Native Gold (Au)

River Cobble with Algae Patina

Weathered Chert or Quartzite pebble (SiO2 dominated)

Chert (with Manganese Oxide coating)

Microcrystalline Quartz (SiO2)

Fossilized Shark Tooth

Elasmobranchii fossil (likely Odontaspididae family)

Chalcedony Geode / Quartz Druzy

Silicon Dioxide (SiO2)

Leopard Skin Jasper

Jasper (Silicon Dioxide with impurities), SiO2

Sandstone (Lithic Wacke)

Clastic sedimentary rock (primarily SiO2 with rock fragments)

Limestone

Limestone (Calcium Carbonate: CaCO3)

Limestone (Weathered)

Calcium Carbonate (CaCO3)

Heliotrope (Bloodstone)

Cryptocrystalline Quartz (SiO2) with inclusions of Hematite (Fe2O3)

Orbicular Jasper (Ocean Jasper variant)

Silicon Dioxide (SiO2) with iron oxide inclusions

Pebble

Lithified clastic rock fragment / Quartz-rich pebble

Biotite (Black Mica)

Biotite - K(Mg,Fe)3(AlSi3O10)(F,OH)2

Chert (Jasper/Agate variety)

Microcrystalline Quartz (SiO2)

Chert (Pink and Yellow Chert)

Microcrystalline Quartz (SiO2)

Chert (Flint Nodules)

Microcrystalline quartz (SiO2)

Sandstone

Arenite (SiO2 based typically)