Anthropogenic Material

Iron-stained quartz-rich rock

Likely quartz with iron-oxide staining (SiO₂ with goethite/limonite); exact identification is uncertain from the photo

Yellow faceted gemstone, likely citrine or synthetic glass

Citrine (quartz, SiO₂) is the leading natural possibility; visual identification is uncertain from the photograph

Limestone

Calcium Carbonate (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Limestone

Calcium Carbonate (CaCO3)

Likely rose quartz

Quartz, silicon dioxide (SiO₂), pink variety

Amethyst crystal cluster

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

Polished turquoise-like stone

Likely turquoise, hydrated copper–aluminum phosphate: CuAl₆(PO₄)₄(OH)₈·4H₂O; identification is uncertain from the photo

Chert or flint nodule

Microcrystalline quartz (SiO₂), commonly chalcedony with possible iron-oxide staining

Polished orbicular basalt (likely)

Basalt, a fine-grained mafic volcanic rock; dark circular features may be amygdales or orbicules

Tumbled coral fragment (likely white calcitic coral)

Calcium carbonate, primarily aragonite or calcite (CaCO₃); exact coral genus cannot be determined from the image

Botryoidal chalcedony (possibly common opal)

Microcrystalline quartz, SiO₂; pale portions may include hydrated silica opal, SiO₂·nH₂O

Quartzite

Quartzite (SiO2)

Polished green-and-white stone, likely serpentine or nephrite jade

Serpentine-group minerals, commonly antigorite/lizardite; possible nephrite (interlocking actinolite–tremolite)

Gravel / Crushed Stone

Aggregate (mixed mineral rock fragments)

Serpentine

Hydrous magnesium iron silicate, (Mg,Fe)3Si2O5(OH)4

Limestone

Calcite (CaCO3)

Vesicular volcanic rock, likely scoria

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

Coquina

Biogenic Limestone (Calcium Carbonate, CaCO3)

Tumbled blue-gray mineral specimen

Indeterminate; possibly dumortierite quartz, sodalite, or dyed stone

Tumbled gray stone, likely quartz-rich pebble

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

Tumbled brown-blue stone, possibly sodalite-bearing jasper

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

Black glassy volcanic rock, likely scoria or obsidian

Vesicular basaltic scoria (probable); possibly dark obsidian

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

Limestone

Calcium Carbonate (CaCO3)

Tumbled granite

Granite, a coarse-grained intrusive igneous rock composed mainly of quartz, feldspar, and mica

Vesicular volcanic rock, likely scoria

Scoria (vesicular basaltic-andesitic rock), composed mainly of plagioclase, pyroxene, and volcanic glass

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

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

Red jasper-like chalcedony pebble

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

Banded Calcite (often sold as Mexican Onyx or Aragonite)

Calcite/Aragonite (Calcium Carbonate, CaCO3)

Sandstone

Arenite (Clastic Sedimentary Rock)

Quartz

Silicon Dioxide (SiO2)

Tumbled or rough turquoise-like specimen

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

Nephrite Jade

Nephrite

Polished amber agate pendant/beads

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