Metamorphic Or Sedimentary Depending On Local Grade

Fossiliferous Limestone / Petoskey Stone (Coral Fossil)

Hexagonaria percarinata / Calcite (CaCO3)

Blue-gray metamorphic rock fragment

Likely slate or phyllite; exact identification is uncertain from the photograph

Exposed aggregate concrete (stone-chip surface)

Portland-cement concrete containing natural aggregate; not a natural rock

Mixed river gravel (alluvial conglomeratic sediment)

Polymictic alluvium; composition includes quartz, feldspar, chert, granite, basalt, and metamorphic rock fragments

Garnet Schist

Almandine Garnet Schist (Fe3Al2(SiO4)3 in Schistose matrix)

Schist

Schist (Metamorphic Rock)

Gray metamorphic rock, likely slate or phyllite

Fine-grained foliated rock, probably quartz–mica slate/phyllite

Greenschist (or Serpentinite) with Quartz-Feldspar Vein

Metabasalt / Greenschist Facies Rock

Garnet-bearing metamorphic rock, likely mica schist

Biotite–garnet schist; commonly includes quartz, feldspar, biotite, and almandine garnet

Weathered mica-rich metamorphic rock

Likely schist or phyllite; composition probably quartz, mica, and feldspar

Marble

Metamorphosed Limestone (principally CaCO3)

Likely slate

Slate, a fine-grained metamorphic rock composed mainly of mica-group minerals, chlorite, and quartz

Gold Nugget / Native Gold

Native Gold (Au)

Manhattan Schist

Manhattan Schist (Aluminous Metasedimentary Rock)

Amphibolite (likely)

Amphibolite, chiefly hornblende and plagioclase feldspar

Greenstone (probable altered basalt)

Chlorite–epidote–actinolite-rich greenschist; composition commonly derived from basalt

Basalt (Weathered River Stone)

Basalt (Extrusive Mafic Igneous Rock)

Quartz Pebble

Silicon dioxide (SiO2)

Epidote in Quartz

Epidote (Ca2(Al,Fe)3(SiO4)3(OH)) in Quartz (SiO2)

Quartz-rich metamorphic rock, likely quartzite

Quartzite; predominantly microcrystalline quartz (SiO₂), possibly with mica or feldspar

Likely tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Greenish quartz-bearing rock, possibly serpentine or aventurine

Tentatively quartz (SiO₂) with green inclusions; exact identification requires testing

Pink quartz-like tumbled stone (possibly dyed quartz or pink chalcedony)

Quartz, SiO₂; appearance may also fit dyed quartzite or pink chalcedony

Fossil tooth, possibly a shark tooth

Unidentified fossilized vertebrate tooth; species cannot be determined from the image

Greenschist

Greenschist facies metamorphic rock; commonly chlorite–actinolite–epidote schist

Sunstone Beads

Feldspar group (Oligoclase / Labradorite)

Dark slate (probable)

Slate, a fine-grained metamorphic rock composed mainly of mica-group minerals and quartz; exact identification is uncertain from the photograph.

Quartz with inclusions

SiO2

Larimar

Pectolite, NaCa2Si3O8(OH)

Mica Schist

Metamorphic rock dominated by micas (muscovite, biotite)

Dark gray metamorphic rock, likely slate or phyllite

Fine-grained foliated rock composed mainly of mica, chlorite, and quartz; exact identification requires testing

Tumbled labradorite (possible)

Labradorite, a plagioclase feldspar; approximately (Ca,Na)(Al,Si)₄O₈

Greenstone / River Jadeite pebble

Metavolcanic rock / Chlorite or Actinolite-rich schist

Almandine Garnet

Iron aluminum silicate (Fe3Al2(SiO4)3)

Weathered sandstone or iron-rich sedimentary fragment

Quartz-rich sandstone, possibly ferruginous sandstone (SiO₂-dominant)

Conglomeratic sandstone / breccia-like gravel rock

Polymictic conglomerate (possibly lithified gravel or concrete-like natural conglomerate)

Zoisite with Ruby (Anyolite)

Zoisite – Ca2Al3(SiO4)3(OH) with inclusions of Ruby (Al2O3:Cr)

Granite Glacial Erratic

Phaneritic Plutonic Felsic Rock (KAlSi3O8 – NaAlSi3O8 – CaAl2Si2O8 – SiO2)

Slate

Slate; fine-grained foliated metamorphic rock, chiefly quartz, mica, and clay minerals

Quartz vein in weathered host rock

Milky quartz (SiO₂), likely in a feldspathic or carbonate-rich matrix

Clear Quartz

SiO2 (Silicon Dioxide)

Schist

Mica Schist (contains muscovite/biotite and quartz)