Organic (Paper And Cellulose)

Chalk

Calcium Carbonate (CaCO3)

Faceted glass-like gemstone object

Likely synthetic glass or cubic zirconia; exact material cannot be confirmed from the image

Petoskey Stone

Hexagonaria percarinata

Tumbled basalt or dark volcanic rock

Basalt; chiefly plagioclase feldspar, pyroxene, and commonly olivine or iron oxides

Polished brown stone, possibly jasper or chert

Indeterminate microcrystalline quartz (SiO₂), likely jasper/chert

Rounded granitic cobble

Granite or granitic gneiss; primarily quartz, feldspar, and mica

Puddingstone

Conglomerate (typically quartz-rich or jasper-rich)

Fossil Rugose Coral (Horn Coral)

Order Rugosa (likely Grewingkia or Heliophyllum species); Calcium Carbonate (CaCO3)

Banded iron formation (BIF)

Banded iron formation; chiefly hematite/magnetite and microcrystalline quartz (chert)

Puddingstone (Quartzite Conglomerate with Jasper inclusions)

Metaconglomerate (Silicon Dioxide, SiO2)

Polished agate geode

Chalcedony (microcrystalline quartz, SiO₂) with quartz druse crystals

Ironstone Concretion

Siderite or Hematite Concretion (FeCO3 or Fe2O3)

Polished brown stone, likely smoky quartz or jasper

Tentatively quartz (SiO₂), possibly smoky quartz; exact identification requires testing

Polished dark stone, likely basalt or black jasper

Basalt (fine-grained plagioclase–pyroxene rock), possibly iron-rich jasper/chert

Likely tumbled yellow-orange mineral or glassy stone

Indeterminate from photograph; possibilities include yellow jasper, calcite, agate, or dyed quartz

Polished fossiliferous limestone

Bioclastic limestone, commonly called fossil limestone or marble-like limestone

Polished fossiliferous limestone

Bioclastic limestone, chiefly calcite (CaCO₃)

Tumbled brown stone, likely jasper or fine-grained quartzite

Uncertain; probable microcrystalline quartz (SiO₂), possibly ferruginous jasper

White Marble

Metamorphic Limestone (CaCO3)

Sandstone with Quartz Vein

Arenite with Quartz (SiO2) Infilling

Optical Calcite (Iceland Spar)

Calcite (Calcium Carbonate, CaCO3)

Dyed Quartz Geode

Silicon Dioxide (SiO2) with artificial pigment

Graphite-rich schist (probable graphite ore)

Graphite schist; chiefly graphitic carbon (C) with quartz, mica, and possibly feldspar

Limestone with Calcite Crystals

Calcium Carbonate (CaCO3)

Pink Granite

Phaneritic Plutonic Rock (Felsic)

Pink Granite

Phaneritic intrusive igneous rock (high Orthoclase Feldspar content)

Diorite

Diorite (intermediate intrusive igneous rock)

Graphite-bearing schist (probable graphite ore)

Graphite (C) in graphitic schist; identification is visual and uncertain

Desert Rose (Baryte or Selenite)

Barium Sulfate (BaSO4) or Hydrous Calcium Sulfate (CaSO4·2H2O)

Pyrite

Iron Disulfide (FeS2)

Slate

Foliated Metamorphic Rock (primarily composed of quartz, illite, chlorite, and micas)

Polished gray pebble, likely quartzite or chert

Quartzite (mostly SiO₂), tentative identification

Horn Coral Fossil

Order Rugosa

Agate

Silicon Dioxide (SiO2)

Pyrite (Fool's Gold)

Iron Sulfide (FeS2)

Polished fossiliferous chert or silicified limestone pebble

Microcrystalline quartz (SiO₂), possibly with calcite and iron-oxide inclusions

Tumbled pink quartz (likely rose quartz)

Quartz, silicon dioxide (SiO₂), pink variety commonly called rose quartz

Sandstone with Iron Banding

Arenite with Hematite or Limonite staining (SiO2 with Fe2O3)

Petoskey Stone

Hexagonaria percarinata (Fossilized Rugose Coral)

Rounded gray river pebble, likely basalt or andesite

Fine-grained mafic to intermediate volcanic rock; commonly basalt (plagioclase + pyroxene, sometimes olivine)

Marble

Recrystallized Calcite (CaCO3)

Polished tiger’s-eye

Quartz (SiO₂), chatoyant fibrous variety; commonly golden-brown tiger’s-eye