Organic (Paper And Cellulose)

Fossilized Coral (Petoskey Stone or Rugose Coral)

Antophyllum (Hexagonaria) or Scleractinia (CaCO3)

Fossil Coral

Cnidaria Anthozoa (Fossilized)

Petrified Wood

Silicified Wood (SiO2 / Quartz pseudomorph after wood)

Polished petrified wood

Silicified wood; primarily microcrystalline quartz (SiO₂) replacing woody tissue

Petrified Wood

Silicified Wood (SiO2)

Petrified Wood

Silicified Wood (SiO2)

Fossilized Coral (Petoskey Stone / Favosites)

Hexagonaria percarinata / Favosites sp. (Calcite, CaCO3)

Tumbled brown agate (likely moss or plume agate)

Microcrystalline quartz, chiefly chalcedony (SiO₂), with iron-oxide and possibly mineral inclusions

Septarian Nodule (Micro-fragment)

Septarian Nodule / Concretion (CaCO3 + CaMg(CO3)2 + Quartz)

Polished petrified wood

Silicified wood; predominantly microcrystalline quartz (SiO₂), often chalcedony

Dendritic Limestone

Calcite with Manganese Oxide (Manganese Dendrites)

Fossilized wood or plant fragment

Petrified wood (silicified fossil wood; commonly Araucarioxylon or related taxa)

Petoskey Stone

Hexagonaria percarinata (Fossilized Rugose Coral)

Petrified Wood

Silicified Wood (SiO2)

Zebra Rock / Zebra Marble

Banded Limestone-Marble Transition

Petrified wood

Silicified wood, commonly quartz/chalcedony (SiO₂) replacing wood tissue

Polished fossiliferous limestone (likely crinoidal or coral limestone)

Bioclastic carbonate rock, chiefly calcite (CaCO₃)

Tumbled fossiliferous limestone

Micritic limestone, likely bioclastic/fossiliferous carbonate rock (predominantly CaCO₃)

Fossil Coral (Rugosa or Solitary Coral)

Rugosa (Order), often referred to as 'Horn Coral' (Lithostrotionella or Grewingkia)

Fossilized wood, likely silicified petrified wood

Silicified wood (fossil wood; commonly quartz/chalcedony replacing organic tissue)

Petrified Wood (Agatized/Silicified Wood)

Silicified Wood (SiO2 - Silicon Dioxide)

Petrified Wood

Silicified wood (Quartz/Chalcedony replacement of cellulose)

Painted River Rock

Painted Quartzite or Smooth Siltstone

Inspirational River Stone (Quartzite)

Metamorphosed Quartz-rich Rock (Quartzite) with SiO2 composition

Ceramic or Polished Stone Heart (Anthropogenic Material)

Glazed Ceramic (Silicon Dioxide based coating on Alumina Silicate body) or Polished Limestone/Marble (Calcium Carbonate, CaCO3)

Sandstone

Arenite

Dyed Agate Geode Slice

Silicon Dioxide (SiO2)

Petoskey Stone

Hexagonaria percarinata

Painted Pet Rock (Quartzite/Sandstone base)

Silicon Dioxide (SiO2) with anthropomorphic acrylic embellishments

Petoskey Stone

Hexagonaria percarinata (Silicified/Calcitic)

Painted Garden Rock (likely Granite or Limestone base)

Silicon Dioxide (SiO2) / Calcium Carbonate (CaCO3) based substrate with Acrylic/Enamel pigments

Painted River Rock

Polished fluvial clast with acrylic/synthetic pigment coating

Biotite (Black Mica)

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

Amethyst (Resin Carving/Orgonite)

Silicon Dioxide (SiO2) with iron impurities

Kaolin (China Clay)

Kaolinite [Al2Si2O5(OH)4]

Petoskey Stone

Hexagonaria percarinata (Fossilized Rugose Coral)

Polished stone sphere, possibly agate or jasper

Likely microcrystalline quartz (SiO₂); exact variety cannot be confirmed from the image

Thunder Egg (Agate Core)

Cryptocrystalline Quartz (SiO2) in Rhyolite/Perlite Matrix

Kaolinite (China Clay / Chalky Claystone)

Al2Si2O5(OH)4

Fossilized Coral (Petoskey Stone type)

Hexagonaria percarinata (Fossilized Rugose Coral)

Sandstone with Quartz/Calcite druse

Arenite with druse (SiO2 or CaCO3)

Sandstone (Quartzose)

Arenite (primarily SiO2)