Manufactured Stone

Black polished stone, likely black obsidian

Obsidian; volcanic glass, predominantly silica-rich rhyolitic composition

Likely quartz-rich brown rock, possibly iron-stained quartz or quartzite

Quartz (SiO₂), possibly in quartzite or iron-oxide-bearing vein material

Goldstone

Aventurine Glass (Man-made)

Asphalt Pavement (with aggregate)

Asphalt concrete

Textile (Upholstery Fabric)

Woven Polyethylene/Polyester or Cotton Blend

Man-made Synthetic Material (Plastic/Composite)

Acrylonitrile Butadiene Styrene (ABS) or High-Impact Polystyrene (HIPS)

Not a geological specimen

N/A (man-made object)

Asphalt Concrete

Bituminous Concrete (Anthropic Rock)

Man-made Jewelry Charm (Enameled Metal)

Not a natural mineral; composed of base metal alloy (likely zinc or brass) and epoxy resin/enamel.

Rhinestone (or glass crystal)

Silicon dioxide (if glass) / Various

Tumbled greenstone / altered basalt pebble

Fine-grained mafic volcanic rock, likely basalt or greenstone; commonly composed of plagioclase, pyroxene, chlorite, epidote, and iron oxides

Colorless faceted gemstone, likely cubic zirconia

Cubic zirconia (synthetic zirconium dioxide, ZrO₂); possibly colorless quartz or laboratory diamond

Quartz

Silicon Dioxide (SiO2)

Turquoise cabochon

Turquoise, hydrated copper aluminum phosphate — CuAl₆(PO₄)₄(OH)₈·4H₂O

Likely polished black-and-white stone fragment

Indeterminate from image; possibly tourmalinated quartz, black-and-white jasper, or coated stone

Weathered limestone pebble

Limestone, chiefly calcite (CaCO₃)

Polished tiger iron

Tiger iron; interlayered hematite, jasper, and crocidolite-quartz (often riebeckite)

Weathered sandstone fragment

Quartz-rich sandstone, likely arkose or lithic sandstone

Polished black stone sphere (likely black basalt or black tourmaline)

Most likely fine-grained basalt (plagioclase–pyroxene); mineral identification is uncertain from the image alone

Faceted colorless gemstone, likely glass or diamond imitation

Unidentified; possibly diamond (carbon, C) or cubic zirconia (zirconium dioxide, ZrO₂)

Small tumbled dark stone, possibly basalt or slag

Likely fine-grained basalt; exact identification is uncertain from the photograph

Water-worn limestone and calcite-rich stones

Limestone, chiefly calcite (CaCO₃), with possible dolomite and minor iron-oxide staining

Concrete or artificial stone core sample

Artificial conglomerate

Note on Image Identification: Textile

N/A (Anthropogenic material)

Mixed gemstone bead bracelet, likely lava rock and aventurine/jade-look beads

Basaltic scoria (vesicular basalt), plus probable serpentine, aventurine, or dyed quartzite beads

Opalite

Synthetic Opalised Glass

Fossilized shell or coral fragment

Indeterminate biogenic carbonate; likely calcite/aragonite (CaCO₃)

Colorless faceted gemstone, likely cubic zirconia

Cubic zirconia (zirconium dioxide, ZrO₂); visual confirmation is unavailable

Black tumbled stone, possibly obsidian

Obsidian (volcanic glass; predominantly SiO₂), identification uncertain from image

Native American Hammerstone / Pitted Stone

Modified lithic artifact (often quartzite, basalt, or granite)

Faience and Carnelian in Egyptian Revival Jewelry

Faience (quartz frit) and Carnelian (chalcedony, SiO2)

Opalite

Synthetic glass (SiO2 + impurities)

Sea Glass

Amorphous Silicon Dioxide (SiO2)

Clear faceted quartz-like gemstone

Probably rock crystal quartz (SiO₂), though the image may show synthetic glass or cubic zirconia

Chert (Flint variety)

Silicon Dioxide (SiO2)

Polished black stone, likely hematite

Hematite (Fe₂O₃), possibly magnetite or a hematite-rich ironstone

Likely polished dark stone or glassy mineral bead

Indeterminate; possibly obsidian, hematite, or a dark agate

Concretionary limestone or calcarenite pebble

Micritic limestone/calcarenite, primarily calcite (CaCO₃)

Black tumbled stone, likely obsidian

Volcanic glass (obsidian), primarily amorphous SiO₂

Goldstone (Red)

Aventurine Glass (Cupriferous glass)

Polished basalt sphere

Basalt; predominantly plagioclase feldspar, pyroxene, and commonly olivine

Rounded white pebble, likely limestone or marble

Calcite-rich carbonate rock; possibly micritic limestone (CaCO₃) or marble