Anthropogenic Material

Vesicular volcanic rock, likely scoria

Scoria; composition commonly basaltic to andesitic, rich in plagioclase and pyroxene

Coquina

Biogenic Limestone (Calcium Carbonate, CaCO3)

Tumbled or rough turquoise-like specimen

Turquoise, hydrated copper aluminum phosphate — CuAl₆(PO₄)₄(OH)₈·4H₂O; identification is uncertain from the image

Red jasper-like chalcedony pebble

Microcrystalline quartz (SiO₂), likely iron-stained chalcedony/jasper

Polished amber agate pendant/beads

Chalcedony (microcrystalline quartz), SiO₂, likely iron-stained yellow-orange agate

Fossilized Bone Fragment

Petrified Osseous Material

Nephrite Jade

Nephrite

Banded chert or agate

Microcrystalline quartz (chalcedony), SiO₂

Red jasper pebble

Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored mainly by iron oxides

Iron-rich metamorphic rock, likely banded iron formation fragment

Hematite–magnetite-rich quartzite (BIF); Fe₂O₃/Fe₃O₄ with SiO₂

Banded Calcite (often sold as Mexican Onyx or Aragonite)

Calcite/Aragonite (Calcium Carbonate, CaCO3)

Tumbled brown-blue stone, possibly sodalite-bearing jasper

Likely quartz-rich jasper with blue sodalite or dumortierite; identification is uncertain from the image

Sandstone

Arenite (Clastic Sedimentary Rock)

Quartz

Silicon Dioxide (SiO2)

Tumbled gray stone, likely quartz-rich pebble

Probable microcrystalline quartz/chalcedony (SiO₂), possibly gray jasper or quartzite

Black rectangular gemstone pendant, likely obsidian or black glass imitation

Most plausibly black obsidian (volcanic glass; SiO₂-rich), though the image cannot exclude synthetic glass or black onyx

Botryoidal chalcedony (likely agate/jasper nodule)

Microcrystalline quartz, SiO₂; commonly mixed with iron oxides and clay minerals

Polished green stone, possibly serpentine or nephrite jade

Serpentine-group minerals, chiefly Mg₃Si₂O₅(OH)₄; alternatively nephrite, a tremolite–actinolite aggregate

Fossil bivalve shell

Likely an extinct or modern-like ribbed cockle/scallop; exact genus requires locality and diagnostic hinge features

Coquina

Bioclastic Limestone

Sandstone

Arenite (primarily SiO2 with Fe2O3)

Rhyolitic Tuff

Rhyolitic Tuff / Pyroclastic rock

Fossilized shell fragment

Likely calcitic or aragonitic bivalve/gastropod shell; exact taxon indeterminate

Polished ocean jasper (orbicular jasper)

Microcrystalline quartz/chalcedony with iron- and manganese-bearing inclusions; SiO₂

Petrified Wood

Silicified Wood (primarily SiO2)

Polished basalt pebble

Basalt, a fine-grained mafic volcanic rock; chiefly plagioclase, pyroxene, and iron-titanium oxides

Red Sandstone

Arenite (SiO2 with Fe2O3)

Weathered gray stone, possibly basalt or granitic rock

Indeterminate fine- to medium-grained silicate rock; possible basalt, diabase, or weathered granite

Likely reddish-brown chert or jasper fragment

Microcrystalline quartz (SiO₂), possibly iron-oxide-bearing jasper

Vesicular volcanic rock, likely weathered scoria

Scoria (vesicular basaltic-andesitic volcanic rock), composition approximately plagioclase, pyroxene, and volcanic glass

Tumbled milky quartz

Quartz, silicon dioxide (SiO₂)

Amethyst cluster

Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron impurities and irradiation

Sandstone

Arenite (composed primarily of SiO2)

Limestone

Calcium Carbonate (CaCO3)

Chert (or Flint)

Microcrystalline Quartz (SiO2)

Quartzite

Quartzite (primarily SiO2)

Limestone

Limestone (Calcium Carbonate, CaCO3)

Chrysocolla-bearing copper ore

Chrysocolla (hydrated copper aluminosilicate), commonly with malachite, azurite, quartz, and limonite

Chert (Flint)

Microcrystalline Quartz (SiO2)

Tumbled brown jasper

Jasper, an opaque microcrystalline variety of quartz (SiO₂), commonly with chalcedony and iron oxides

Weathered iron-rich rock, possibly jasper or ironstone

Likely limonite/goethite-bearing siliceous rock; exact identification requires hardness and streak tests

Polished Mexican “Crazy Lace” agate tower

Microcrystalline quartz (chalcedony), SiO₂, with iron-oxide inclusions