Mineraloid (Human Made Geological Specimen)

Chert (Flint)

Cryptocrystalline Quartz (SiO2)

Not a rock, mineral, or geological specimen

Obsidian

Obsidian (Volcanic Glass)

Chert (Common Opal/Jasper variety)

Cryptocrystalline Quartz (SiO2)

One Pound Coin (UK)

Nickel-Brass Alloy (Cu-Zn-Ni)

Toast

Triticum aestivum (processed)

Crushed Stone / Gravel

Aggregatus saxum (variable mineral composition)

Opalite

Man-made synthetic glass with opalescent effects (SiO2 + metal oxides)

Banded agate pendant (likely carnelian or brown-and-white chalcedony agate)

Agate, a banded variety of chalcedony; microcrystalline quartz, SiO₂, with iron-oxide coloration

Chert Arrowhead

Cryptocrystalline Quartz (SiO2)

Limonite (Yellow Ochre)

Hydrated iron(III) oxide-hydroxide (FeO(OH)·nH2O)

Cullet Glass (sometimes mistaken for Blue Obsidian or Slag)

Amorphous Silicon Dioxide (SiO2) with chemical additives (e.g., Cobalt for blue color)

Man-made Ceramic / Clay Figurine

Aluminosilicate Ceramic (Processed Clay)

Chert (Yellow Jasper/Flint)

Chert (Microcrystalline Silicon Dioxide, SiO2)

Concrete

Anthropogenic Sedimentary Rock (Hydrated Calcium Silicate)

Aluminum Slag

Anthropogenic Aluminum (Al)

Man-made Crystal (Lead Glass)

Lead oxide-doped Silica Glass (approx. SiO2 + PbO)

Eroded Brick or Pumice-like Scoria

Vesicular Basalt / Scoria (Anthropogenic variant: Eroded Firebrick)

Opalite

Synthetic Opalized Glass

Amber

Succinite (Carbon-based organic compound; approximate formula C10H16O)

Goldstone

Aventurine glass (Synthetic glass with copper inclusions)

Goldstone and pink quartz bead strands

Goldstone is aventurescent copper-bearing glass; pink beads are likely rose quartz (SiO₂), though dyed or glass imitations are possible

Flint (or Chert with cortex)

Silicon dioxide (SiO2)

Dark rounded pebble, likely basalt or slag

Probable fine-grained mafic rock; possibly basalt (plagioclase–pyroxene) or industrial iron/steel slag

Pearl-and-gemstone insect brooch

Pearl: nacre (aragonite, CaCO₃); colored stones are likely synthetic or natural corundum/spinel/glass, not determinable from the image

Opalite

Synthetic Glass (Hydrated Crystalline Silicon Dioxide simulation)

Chert (varietal Chalcedony or Flint)

Silicon dioxide (SiO2) - Microcrystalline Quartz

Clear Quartz (Rock Crystal) Bead

Silicon Dioxide (SiO2)

Quartz pebble in concrete

Quartz (SiO₂), embedded in Portland-cement concrete

Note: Item is not a geological specimen

Homo sapiens (Dermal Appendage: Pilus)

Lemon (Mock specimen mimicking Citrine/Sulfur)

Citrus x limon

Sandstone (Pet Rock)

Clastic sedimentary rock (primarily SiO2)

Concrete with Aggregate

Composite construction material; primary matrix is Calcium Silicate Hydrate (C-S-H)

Pearl (Biogenic Mineraloid)

Calcium carbonate (Aragonite) and Conchiolin, CaCO3

Goldstone (blue-goldstone–style glass) beads

Artificial aventurine glass, typically silica glass with copper inclusions; not a natural mineral

Uncertain small metallic-looking mineral/rock fragment

Indeterminate; possibly galena-bearing rock or metallic slag

Sandstone (with concrete/human-made layer)

Clastic Sedimentary Rock (primarily Quartz/Feldspar grains)

Crackled Quartz (Blue Dyed)

Silicon Dioxide (SiO2) with anthropogenic dye

Cowrie Shell Fossil

Cypraea sp.

Rose Gold (Copper-Gold Alloy)

Aurum-Cuprum Alloy (Au-Cu)

Carved Mottled Greenish-Yellow Crystal/Glass Object

Unknown; possibly a form of quartz (chalcedony/jadeite/nephrite) or glass/resin.

Chert (often called Flint)

Chert (Microcrystalline Quartz, SiO2)