Mineral Based Human Made Alloy

Titanium Aura Quartz

Titanium-coated Silicon Dioxide (SiO2)

Opalite

Synthetic Opalised Glass

Chert (Flint)

Silicon Dioxide (SiO2)

Chert (varietal Chalcedony or Flint)

Silicon dioxide (SiO2) - Microcrystalline Quartz

Man-made Carved Stone (Scream Mask/Skull motif)

Carved Soapstone or Serpentine-rich rock

Opalite

Synthetic Glass (typically Silica/Magnesium based with metal additives)

Coquina / Fossiliferous Limestone

Coquina (composed primarily of Calcium Carbonate / CaCO3)

Chert (Yellow Jasper/Flint)

Chert (Microcrystalline Silicon Dioxide, SiO2)

Chert (often called Flint)

Chert (Cryptocrystalline Quartz, SiO2)

River Pebble

Weathered Rock Fragment

Amber

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

Malaysian 50 Sen Coin

Coinage (specific alloy unknown without metallurgical analysis, but typically brass or bronze for this denomination and era)

Asphalt Concrete

Bituminous Concrete / Asphaltic Composite

Concrete fragment with Aggregate

Anthropogenic Concrete with Calcarious and Siliceous Aggregate

Blue Celestite

Celestine (Strontium Sulfate, SrSO4)

Granite

Granite (a plutonic rock)

South Korean 100 Won Coin (Cupronickel)

Cupronickel Alloy (75% Cu, 25% Ni)

Granite

Phaneritic Igneous Rock (composed primarily of Quartz, Alkali Feldspar, and Plagioclase)

Dark rounded pebble, likely basalt or slag

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

Costume Jewelry with Synthetic Gemstones

Synthetic Cubic Zirconia and Glass (SiO2 / ZrO2)

Fossilized Coral (Petoskey-style)

Hexagonaria percarinata (Fossilized Rugose Coral)

Lepidolite

K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2

Goldstone

Avventurina (Cu + SiO2 glass)

Iron Meteorite

Siderite (Iron-Nickel Alloy)

Flint (or Chert with cortex)

Silicon dioxide (SiO2)

Chert (often called Flint or Jasper if reddish)

Microcrystalline Quartz (SiO2)

Granite

Granite (composed primarily of Quartz, Feldspar, and Mica)

Fired Clay Brick (Anthropic Rock substitute)

Anthropogenic polycrystalline ceramic (predominantly Mullite and Quartz: Al6Si2O13 + SiO2)

Chert

Silicon dioxide (SiO2)

Granite

Phaneritic Plutonic Felsic Rock

Quartzite

Quartzite (SiO2)

Gold

Aurum (Au)

Transit Token (RTD Denver)

Nickel-plated brass or bronze alloy (Cu-Sn-Zn-Ni)

Diamond (as set in a metal alloy ring)

Diamond (Pure Carbon, C)

Crackled Quartz (Dyed)

Silicon Dioxide (SiO2)

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

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

Granite

Granite (Felsic Plutonic Rock)

Chert (varietal Flint)

Microcrystalline quartz (SiO2)

Granite

Granite (Phaneritic Quartz-Feldspar intrusive rock)

Polished black stone egg, probably black obsidian

Obsidian, a natural volcanic glass; composition primarily silica-rich glass (approximately SiO₂), with variable iron and other trace elements

Dyed Quartz (often sold as 'Blue Quartz' or 'Blue Agate')

Silicon Dioxide (SiO2) with artificial pigment

Eroded Brick or Pumice-like Scoria

Vesicular Basalt / Scoria (Anthropogenic variant: Eroded Firebrick)