Anthropogenic Material

Tektite (likely indochinite)

Natural silica-rich impact glass; predominantly amorphous SiO₂ with aluminum, iron, magnesium, calcium, and sodium

Granite (Unakite / Feldspar-rich Granite)

Granite (composed of Potassium Feldspar, Quartz, and Biotite/Epidote)

Gastropod shell fragment

Calcareous mollusk shell; primarily aragonite or calcite (CaCO₃)

Brick veneer, likely manufactured from clay-rich shale

Fired clay brick; chiefly aluminosilicate minerals, commonly mullite and glassy silicate phases after firing

Polished dark agate or jasper specimen

Cryptocrystalline quartz (chalcedony), SiO₂; exact identification is uncertain from the image

Dendritic jasper/chalcedony

Silica-rich microcrystalline quartz (SiO₂) with manganese-oxide dendrites

Turquoise ring (likely stabilized or imitation turquoise)

Turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O; exact material is uncertain from the image

Blue Sphalerite (likely dyed or treated Druzy Quartz/Agate)

Zinc Sulfide (ZnS) or Silicon Dioxide (SiO2) with trade-name enhancement

Coquina

Coquina (Bioclastic Limestone)

Black-and-white bicolored pebble

Likely basalt with a pale felsic or carbonate coating/inclusion; exact identification requires testing

Scoria (vesicular basalt)

Vesicular basalt, commonly called scoria; chiefly plagioclase, pyroxene, and iron-rich volcanic glass

Vesicular volcanic rock (likely scoria)

Scoria, a vesicular basaltic to andesitic volcanic rock

Coquina

Bioclastic Limestone

Polished stone clock face, likely agate or jasper

Unconfirmed silica-rich material; possibly banded chalcedony (SiO₂)

Red coral bead strand (likely dyed or treated coral)

Corallium spp. (calcareous coral skeleton; primarily CaCO₃)

Crushed Stone / Gravel

Aggregate (mixed lithology)

Quartz-bearing pegmatitic rock, likely granite/pegmatite

Feldspar–quartz pegmatite; chiefly K-feldspar, plagioclase, quartz, and possible mica

Tiger’s-eye bead bracelet

Chatoyant quartz, principally quartz (SiO₂) with pseudomorphic fibrous crocidolite/goethite inclusions

Black beaded bracelet, likely black onyx or glass

Possibly chalcedony (microcrystalline quartz, SiO₂); the beads may instead be man-made glass

Small brown jasper or chert fragment

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

Petrified Wood

Silicified Wood (SiO2)

Iron-rich lateritic soil / weathered ferruginous rock

Laterite, primarily hydrated iron oxides (goethite/limonite) with clay minerals and quartz

Polished banded stone, likely black marble or banded gneiss

Graphitic banded marble or quartz-feldspar biotite gneiss; exact identification requires testing

Sandstone

Arenite (SiO2 primarily)

Fossilized coral with attached shell

Likely fossil coral (Scleractinia or Tabulata), with a bivalve or gastropod shell; exact identification requires microscopy

Beads (likely glass or man-made material)

N/A (artificial material)

Tourmaline in Quartz

Schorl in SiO2

Limestone

Calcium Carbonate (CaCO3)

Quartzite

Quartzite (SiO2-rich metamorphic rock)

Sandstone

Arenite (primary component SiO2)

Sandstone

Arenite (SiO2 based)

Faceted Gemstone

Unknown transparent mineral, possibly Diamond (C), Cubic Zirconia (ZrO2), Quartz (SiO2), or Glass

Polished banded jasper (likely picture jasper)

Microcrystalline quartz, chiefly SiO₂; jasper with iron-oxide staining

Asphalt Chunk

Asphalt concrete

Polished tiger’s-eye

Quartz variety, SiO₂, with crocidolite-derived iron inclusions

Smoky quartz (likely)

Quartz, silicon dioxide (SiO₂), smoky variety

Tumbled orange agate or carnelian

Microcrystalline quartz (chalcedony), SiO₂; orange coloration commonly from iron oxides

Likely weathered quartz-rich rock fragment

Uncertain; possibly quartz-bearing granitic or metamorphic material (SiO₂-dominant)

White pebbles (rock material not identifiable from the image)

Undetermined; the smooth, pale pieces could be quartz, quartzite, or another light-colored rock

Tumbled pink quartz, likely dyed

Quartz (silicon dioxide, SiO₂), probably artificially colored chalcedony or milky quartz

Tumbled hematite

Hematite (Fe₂O₃), commonly sold as “magnetic hematite” when synthetic or magnetized

Pink quartz (rose quartz), possibly quartz-rich rock

Quartz, silicon dioxide (SiO₂), commonly rose quartz