Mineral, Sediment

Pyrite Schist

Metamorphic rock containing FeS2 (Pyrite) with mica and quartz

Red jasper (likely iron-rich chert)

Microcrystalline quartz (SiO₂) colored by hematite/goethite

Fossil scallop shell

Fossilized bivalve mollusk; likely Pectinidae or a related pectinid

Ammonite fossil in matrix

Fossilized ammonoid cephalopod; likely an ammonite such as Dactylioceras or a related Jurassic taxon

Petrified Wood

Fossilized wood / Silicified wood

Fossil shell fragment (likely bivalve)

Bivalvia indeterminate; shell material chiefly aragonite or calcite (CaCO₃)

Chalcedony or chert pebble with iron-oxide staining

Microcrystalline quartz (SiO₂), possibly a weathered chert or flint nodule

Fossilized bivalve shell fragment

Fossil mollusk shell, likely a pectinid or related bivalve; original shell composed mainly of aragonite or calcite, now partly mineralized

Rounded gray river pebble, likely basaltic rock

Fine-grained basalt or andesite; exact identification requires testing

Small quartz-rich pebble or rock fragment

Quartz (silicon dioxide, SiO₂), possibly with iron-oxide staining or host-rock inclusions

Concretion

Various mineral compositions, typically carbonate or iron oxide cemented sediment

Tumbled fossil-bearing limestone or chert

Microcrystalline calcite (limestone), possibly silicified; fossil fragments visible

Blue-gray kyanite crystal

Kyanite, Al₂SiO₅

Fossil Shark Tooth

Chondrichthyes (class)

Possible fossilized bone or tooth fragment

Indeterminate fossilized vertebrate material; mineralized hydroxyapatite replaced or coated by silica/carbonate

Fossil Coral

Scleractinia (Fossilized Coral) / Calcium Carbonate (CaCO3) or Silica (SiO2)

Quartzite with inclusions

Quartzite

Ironstone Concretion

Siderite or Hematite Concretion

Sandstone Concretion

Clastic sedimentary rock (primarily Silica, SiO2, or Calcium Carbonate, CaCO3)

Concretion

Septarian Concretion (Clay-Ironstone Nodules)

Sandstone Concretion

Ferruginous Sandstone Concretion (SiO2 + FeO(OH))

Petoskey Stone

Hexagonaria percarinata (Fossilized Rugose Coral)

Sandstone Concretion

Clastic Sedimentary Concretion (primarily SiO2 with Fe2O3 cement)

Zebra Jasper (Zebra Stone)

Silicon Dioxide (SiO2) with iron oxide and manganese inclusions

Polished picture jasper (likely a jasper-and-chalcedony slab)

Microcrystalline quartz, SiO₂; jasper is an opaque variety of chalcedony

Red Jasper

Silicon Dioxide (SiO2) with iron oxide inclusions

Brachiopod Fossil in Matrix

Phylum Brachiopoda

Wishing Stone (Basalt or Siltstone with Quartz/Calcite Vein)

Basalt (SiO2+MgO+FeO) or Siltstone with a Quartz (SiO2) or Calcite (CaCO3) vein

Weathered iron-rich rock, likely limonite/goethite-bearing sandstone or laterite

Hydrated iron oxides, chiefly limonite (FeO(OH)·nH₂O) and goethite (α-FeO(OH)), possibly cementing sandstone

Weathered iron-stained quartzite or sandstone cobble

Quartzite, chiefly SiO₂, with iron-oxide staining; possibly ferruginous sandstone

Fossil gastropod (snail shell)

Gastropoda; likely a small spiral shell preserved/replaced by calcium carbonate

Picture Jasper

Silicon Dioxide (SiO2) with iron oxide and mineral impurities

Weathered fossil shell fragment

Likely a fossilized bivalve or gastropod fragment; exact taxon cannot be determined from one view

Tumbled brown jasper

Microcrystalline quartz/chalcedony (SiO₂), iron-oxide colored

Carved limestone architectural fragment

Limestone, predominantly calcite (CaCO₃), possibly weathered fossiliferous or oolitic limestone

Petrified Wood

Silicified Wood (SiO2)

Weathered chert or chalcedony pebble

Microcrystalline quartz (SiO₂), likely chert/chalcedony

Likely water-worn gray pebble

Not identifiable to a specific rock from this image; possibly fine-grained basalt or another dark river-worn rock

Jasper / Quartzite

SiO2

Carbonate Beach Sand

Biogenic Carbonate Sediment (CaCO3)

Sea Glass (Frosted Glass Fragment)

Amorphous Silica (Anthropogenic Sediment)

Turquoise

CuAl6(PO4)4(OH)8·4H2O