Pyrite (Polished Palm Stone)
Iron disulfide (FeS2)
mineral
Category
Organic (Paper And Cellulose)
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Quartzite River Rock
Quartzite (primarily SiO2)
metamorphic
Kaolinite (China Clay)
Kaolinite (Al2Si2O5(OH)4)
sedimentary
Fossil Coral (Petoskey Stone / Hexagonaria)
Hexagonaria percarinata (Silicified/Calcite Replacement Coral)
fossil
Pyrite
Iron Disulfide (FeS2)
mineral
Tumbled agate or chalcedony
Microcrystalline quartz, SiO₂
mineral
Polished dendritic agate (likely moss agate)
Microcrystalline quartz, SiO₂, with iron/manganese oxide inclusions
gemstone
Tumbled agate/chalcedony pebble
Microcrystalline quartz (SiO₂), likely gray chalcedony with iron-oxide or other mineral inclusions
mineral
Polished orbicular granite (likely gabbroic granite)
Granite, chiefly quartz (SiO₂), feldspar, and biotite/amphibole; exact variety uncertain from the photograph
igneous
Polished banded gneiss pebble
Gneiss, chiefly quartz–feldspar–mica; exact mineralogy uncertain from image
metamorphic
Petoskey Stone (Fossilized Rugose Coral)
Hexagonaria percarinata
fossil
Chalk
Micrite (primarily Calcium Carbonate or CaCO3)
sedimentary
Grey Banded Agate
Chalcedony (Silicon Dioxide, SiO2)
mineral
Garnet Schist
Almandine Garnet Schist (Fe3Al2(SiO4)3 in Schistose matrix)
metamorphic
Marble
Recrystallized Calcite (CaCO3)
metamorphic
Petoskey Stone
Hexagonaria percarinata
sedimentary
Agate (Geode nodule)
Cryptocrystalline Quartz (SiO2)
mineral
Mixed rock and mineral collection; individual pieces are too small and indistinct for reliable identification
Undetermined; several specimens appear to be common silicate rocks or minerals
mineral
Tumbled greenstone/chlorite-rich pebble
Likely chlorite-rich greenschist or altered basalt; exact identification requires testing
metamorphic
Tumbled yellow chalcedony (likely yellow jasper)
Microcrystalline quartz, SiO₂; chalcedony/jasper variety
mineral
Mica
Phlogopite or Biotite group (KMg3(AlSi3O10)(F,OH)2 / K(Mg,Fe)3AlSi3O10(OH)2)
mineral
Sandstone (Iron-stained)
Sandstone (dominated by Quartz, SiO2, with Iron Oxide impurities)
sedimentary
Sandstone
Arenite (SiO2 primarily)
sedimentary
Sandstone (Lithic Sandstone / Greywacke)
Sandstone (SiO2 rich clastic sedimentary rock)
sedimentary
Chalk
Calcium Carbonate (CaCO3)
sedimentary
Banded Agate (with Quartz Geode Center)
Silicon Dioxide (SiO2)
mineral
Orgonite Pyramid (containing Amethyst and mixed minerals)
Silicon Dioxide (SiO2) in synthetic resin
gemstone
Orthoceras fossil in limestone
Orthoceras (extinct genus of cephalopod)
sedimentary
Tumbled banded agate
Microcrystalline quartz (chalcedony), SiO₂, with band-forming impurities
mineral
Banded iron formation fragment (polished ironstone)
Banded iron formation; hematite/magnetite-rich chert, commonly approximated as Fe₂O₃–Fe₃O₄ with SiO₂
sedimentary
Barite
Barium sulfate (BaSO4)
mineral
Orthoceras Fossil
Orthoceras regulare (Class Cephalopoda, Order Orthocerida)
fossil
Ammonite Fossil in Matrix
Ammonoidea subclass (e.g., Arietites or similar genera)
fossil
Banded Agate (Dyed / Polished)
Microcrystalline Quartz (SiO2)
mineral
Dyed Agate Geode
Silicon Dioxide (SiO2) - Banded Chalcedony
mineral
Tumbled jasper, likely picture or brecciated jasper
Microcrystalline quartz (SiO₂) with iron-oxide and other mineral impurities
gemstone
Orange Moss Agate / Carnelian Agate
Silicon dioxide (SiO2) - variety Chalcedony
sedimentary
Sandstone (Water-worn Cobble)
Arenite (variable composition, primarily SiO2)
sedimentary
Kaolin Clay in Saprolite Profile
Kaolinite (Al2Si2O5(OH)4) within Weathered Pegmatite/Granite
sedimentary
Orthoceras Fossil in Limestone
Orthoceras regulare
sedimentary
Rounded gray river pebble, likely granite or gneiss
Indeterminate granitic rock; commonly quartz + feldspar + mica, possibly gneissic
igneous
Banded Iron Formation (BIF)
Banded Iron Formation (BIF)
sedimentary