Man Made Object (Ring)

Gemstone bead necklace (likely citrine or yellow quartz)

Quartz, SiO₂; precise identification is uncertain because the beads are blurred and metal settings obscure them

Ambergris

Ambrein-rich Calculus

Weathered pegmatite or feldspar-rich granite fragment

Granitic pegmatite, composed mainly of potassium feldspar and quartz, with minor mica; exact identification is uncertain from the photograph

Rutilated Quartz (likely Citrine or Smoky Quartz with Rutile inclusions)

SiO2 with TiO2 inclusions (Quartz with Rutile)

Pink quartz crystal, possibly rose quartz

Quartz (silicon dioxide, SiO₂), likely pink quartz/rose quartz

Black Slate

Slate (Metamorphic Rock)

Petrified Wood

Silicified Wood (SiO2 permineralization)

Jadeite

NaAlSi2O6; Jadeite silicate mineral

Calcite (or Alabaster, if truly carved)

Calcium Carbonate (CaCO3)

Polished citrine quartz point

Quartz, silicon dioxide (SiO₂), yellow-orange variety commonly sold as citrine; possibly heat-treated amethyst

Spiny Oyster Shell

Spondylus varians (Biogenic Calcium Carbonate)

Tumbled dark blue-green stone, likely labradorite or indigo gabbro

Indeterminate; possible feldspar-rich labradorite (plagioclase, NaAlSi₃O₈–CaAl₂Si₂O₈)

Small rounded pebble

Unidentified lithic clast; likely fine-grained sandstone, mudstone, or basalt

Andesite Porphyry (River Cobble)

Porphyritic Andesite

Fossilized Wood / Petrified Wood

Petrified Wood (Silicified Flora)

Petrified Wood

Silicified Wood (primarily SiO2)

Chert (Iron-stained)

Silicon Dioxide (SiO2)

Slate

Foliated metamorphic rock (Slate)

Amethyst (as seen in jewelry)

Amethyst (Silicon Dioxide SiO2 + Fe4+)

Petrified Wood

Silicified Wood (primarily SiO2)

Calcite

Calcium Carbonate (CaCO3)

Petrified Wood and Mixed Rocks

Silicified Wood (SiO2)

Carnelian

Silicon Dioxide, variety of chalcedony (SiO2)

Cobalt Glass Slug (Man-made Glass)

Amorphous Silica with Cobalt Oxide (SiO2 + CoO)

Native Silver

Silver (elemental Ag)

Fluorite (likely Green Fluorite variant)

Calcium Fluoride (CaF2)

Pyrite

Iron Sulfide (FeS2)

Cubic Zirconia (as a jewelry specimen)

Zirconium dioxide (ZrO2)

Black Jasper (Black Onyx substitute)

Silicon Dioxide (SiO2) with carbonaceous impurities

Malachite

Malachite (Cu2CO3(OH)2)

Jade (Nephrite)

Nephrite (Ca2(Mg, Fe)5Si8O22(OH)2)

Larimar

Pectolite (NaCa2Si3O8(OH))

Diamond (in Ring Setting)

Diamond (C)

Ruby (in a ring setting)

Corundum (Al2O3:Cr)

Diamond

Diamond (pure Carbon, C)

Petrified Wood

Silicon Dioxide Fossilized Wood (SiO2)

Liesegang Ring Siltstone

Siltstone with iron oxide Liesegang bands

Garnet

Garnet group [X3Y2(SiO4)3]

Tumbled blue stone, likely blue aventurine or dyed quartzite

Quartz (SiO₂), likely with inclusions or artificial dye; exact identification requires testing

Heart-shaped Pebble (Limestone/Quartz)

Calcium Carbonate (CaCO3) / Silicon Dioxide (SiO2)

Nickel coin (U.S. currency)

Cupronickel (75% Copper, 25% Nickel alloy)

Fossiliferous Limestone (Crinoidal Limestone)

Bioclastic grainstone (CaCO3)