Mineraloid (Human Made Geological Specimen)

Aluminum Slag

Anthropogenic Aluminum (Al)

Not a rock, mineral, or geological specimen

Greenstone / serpentinite carving

Serpentinite, chiefly serpentine-group minerals (antigorite, lizardite, or chrysotile); exact identification requires testing

Chert (Common Opal/Jasper variety)

Cryptocrystalline Quartz (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

Chert Arrowhead

Cryptocrystalline Quartz (SiO2)

One Pound Coin (UK)

Nickel-Brass Alloy (Cu-Zn-Ni)

Banded agate cabochon

Microcrystalline quartz (chalcedony), SiO₂

Tumbled fossil shark tooth pendant

Likely fossilized shark tooth, possibly Otodus or Carcharhinus; exact species cannot be confirmed from the image

Amethyst gemstone ring

Quartz, purple variety — SiO₂

Opalite

Synthetic Opalite Glass (Silicon Dioxide)

Opalite

Synthetic Opalized Glass

Limonite (Ironstone)

Limonite (mixture of hydrated iron oxides, primarily Goethite α-FeO(OH))

Pearl-and-gemstone insect brooch

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

Native silver fragment (probable)

Silver, Ag; possibly silver-bearing sulfide or plated metal

Opalite

Man-made Glass (SiO2 + additives)

Tumbled clear quartz (rock crystal)

Quartz, silicon dioxide (SiO₂)

Chert (Yellow Jasper/Flint)

Chert (Microcrystalline Silicon Dioxide, SiO2)

Tumbled yellow jasper or chalcedony

Microcrystalline quartz, SiO₂; likely iron-oxide-bearing jasper/chalcedony

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

Concrete

Anthropogenic Sedimentary Rock (Hydrated Calcium Silicate)

Carnelian cabochon pendant

Carnelian, orange-red chalcedony (microcrystalline quartz, SiO₂)

Blue faceted gemstone, likely synthetic sapphire or blue glass

Corundum (Al₂O₃) if sapphire; identity cannot be confirmed visually

Chert (varietal Chalcedony or Flint)

Silicon dioxide (SiO2) - Microcrystalline Quartz

Dark rounded pebble, likely basalt or slag

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

Polished dark gray stone, likely basalt or fine-grained andesite

Basalt/andesite; primarily plagioclase feldspar, pyroxene, and possibly olivine or magnetite

Flint (or Chert with cortex)

Silicon dioxide (SiO2)

Sandstone (with concrete/human-made layer)

Clastic Sedimentary Rock (primarily Quartz/Feldspar grains)

Likely weathered granite or granitic gneiss fragment

Granite; primarily quartz, feldspar, and mica

Polished black stone, likely black obsidian

Volcanic glass; predominantly rhyolitic silica glass (SiO₂-rich)

Concrete aggregate surface

Human-made cementitious composite; primarily calcium-silicate-hydrate cement with mixed silicate aggregate

Fossil shark tooth, likely megalodon

Fossilized shark tooth; possibly Otodus megalodon (formerly Carcharocles megalodon)

Yellow Ocher (Limonite)

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

Eroded Brick or Pumice-like Scoria

Vesicular Basalt / Scoria (Anthropogenic variant: Eroded Firebrick)

Toast

Triticum aestivum (processed)

Polished gemstone tower assortment

Primarily quartz varieties and simulants; apparent amethyst (SiO₂), rose quartz (SiO₂), clear quartz (SiO₂), fluorite (CaF₂), sodalite, malachite, and possibly dyed or composite stones

Dark, weathered stone—possibly basalt or slag

Indeterminate; likely fine-grained basalt (plagioclase–pyroxene)

Polished/tumbled brown-and-white mineral fragment

Indeterminate; possibly quartz-rich jasper, brecciated jasper, or an iron-stained quartz mineral

Opalite

Synthetic Fluorescent Glass (SiO2 + impurities)

Gemstone jewelry ensemble

Likely mixed gemstone and glass-bead jewelry; exact stones cannot be determined from the image

Sea Glass

Man-made silicate glass (Amorphous silicon dioxide)

Carved serpentine pendant

Serpentine-group minerals, commonly antigorite/lizardite (Mg₃Si₂O₅(OH)₄), possibly mixed with chlorite or other inclusions