Mineraloid (Human Made Geological Specimen)

Polished yellow jasper or serpentine bead

Jasper: microcrystalline quartz (SiO₂); possible serpentine: Mg₃Si₂O₅(OH)₄

Decorative gemstone bracelet or jewelry

Unidentifiable from the blurred image; likely colored glass or synthetic stones, possibly mixed gemstone beads

Man-made Synthetic Material (Plastic/Composite)

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

Black Obsidian

Amorphous volcanic glass (SiO2)

Limonite (with Pyrite)

Limonite (Hydrated Iron Oxide) - FeO(OH)·nH2O

Chert (and Jasper/Chalcedony mixture)

Microcrystalline Quartz (SiO2)

Chert (Flint)

Silicon Dioxide (SiO2)

Painted Garden Rock

Coated Siltstone or Mudstone

Man-made Slag (Industrial Byproduct)

Anthropogenic Glassy Residue

Chert / Flint Handaxe

Cryptocrystalline Quartz (SiO2)

Tumbled pegmatitic granite

Coarse-grained granite/pegmatite, chiefly quartz, feldspar, and biotite or amphibole

Goldstone (Brown)

Aventurine Glass (Silicon Dioxide infused with Copper crystals)

Chert / Flint

Microcrystalline Quartz (SiO2)

Kidney Stone

Nephrolithiasis (Calcium Oxalate, Hydroxyapatite, or Uric Acid)

Flint or chert artifact

Microcrystalline quartz (SiO₂), likely worked flint/chert

Dark basalt or industrial slag (tentative)

Basalt; predominantly plagioclase and pyroxene, possibly with olivine

Polished dendritic agate or jasper

Microcrystalline quartz (SiO₂), likely chalcedony with iron/manganese dendrites

Polished black obsidian

Volcanic glass; primarily silica-rich rhyolitic composition (approximately 70–80% SiO₂)

Man-made Jewelry Charm (Enameled Metal)

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

Glass / Silicon Dioxide (Man-made)

SiO2 (Amorphous Silicon Dioxide)

Fossil or modern bivalve shell

Calcium carbonate shell, likely aragonite (CaCO₃); exact species cannot be determined from the image

Snowflake Obsidian

Volcanic glass (SiO2) with Cristobalite (SiO2) inclusions

Opalite

Synthetic Opalite Glass / Opalized Glass

Polymictic conglomerate or breccia (possibly concrete-like aggregate)

Lithified polymictic gravel; clasts may include basalt, granite, quartzite, and other silicates

Polished black obsidian pyramid/block

Obsidian — natural volcanic glass, chiefly rhyolitic silica (approximately 70–75% SiO₂)

Tumbled rose quartz

Quartz, silicon dioxide (SiO₂), pink variety

Chert

Microcrystalline quartz (SiO2)

Coquina and Oyster Fossil Rock

Coquina limestone (Calcium Carbonate, CaCO3) containing fossilized Crassostrea / bivalve shells

Tumbled lavender quartz (likely lepidolite-bearing quartz or dyed quartz)

Quartz, SiO₂; possible lepidolite mica inclusions

Chert / Flint (Flaked Stone Tool / Projectile Point)

Microcrystalline Quartz (SiO2)

Chert (Arrowhead/Artifact Fragment)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Snowflake Obsidian

Volcanic Glass (spherulitic Obsidian) - SiO2 (with Cristobalite inclusions)

Snowflake Obsidian (Flower Jasper variant)

Vitreous volcanic silicate with cristobalite inclusions

Obsidian (black volcanic glass)

Obsidian; predominantly silica-rich volcanic glass, commonly rhyolitic (approximately 70–75% SiO₂)

Snowflake obsidian

Volcanic glass (mostly rhyolitic) with cristobalite or feldspar spherulites

Chert

Microcrystalline quartz (SiO2)

Tumbled labradorite

Labradorite, a calcium-rich plagioclase feldspar; approximately (Ca,Na)(Al,Si)₄O₈

Flint/Chert Nodule in Limestone

Sedimentary rock containing microcrystalline quartz (SiO2) within a calcium carbonate (CaCO3) matrix

Chert Arrowhead (Lithic Artifact)

Microcrystalline Quartz (SiO2)

Polished hematite (speculative)

Hematite, α-Fe₂O₃; possibly hematite-rich ironstone

Polished labradorite cabochon

Labradorite, a calcic plagioclase feldspar; approximately (Ca,Na)(Al,Si)₄O₈

Obsidian

Volcanic Glass (predominantly SiO2)