Mineraloid (Human Made Geological Specimen)

Likely polished greenstone or serpentine inlay

Serpentine-group mineral, commonly antigorite/lizardite; possibly nephrite jade

Concrete fragment with Aggregate

Anthropogenic Concrete with Calcarious and Siliceous Aggregate

Small tumbled stone, likely quartz-rich pebble

Probably microcrystalline quartz (SiO₂), but the image is insufficient for a definitive identification

Chert (Jasper variety)

Silicon Dioxide (SiO2)

Pearl

Calcium Carbonate (Aragonite or Calcite) and Conchiolin

Terrazzo flooring containing marble aggregate

Marble (recrystallized calcite, CaCO₃) aggregate in cementitious terrazzo

Fulgurite

Fulgurite (Lechatelierite-rich fused silica)

Dyed mineral cluster, likely calcite or aragonite

Calcite (CaCO₃) or aragonite (CaCO₃), artificially color-enhanced

Polished fossilized wood (likely petrified wood)

Silicified wood; primarily quartz (SiO₂) replacing wood tissue

Goldstone (blue/black aventurine glass)

Man-made aventurine glass; silica glass containing metallic copper or other glittering inclusions

Tumbled metallic-gray stone, likely hematite or magnetite

Hematite (Fe₂O₃) or magnetite (Fe₃O₄); exact identification requires testing

Chert

Microcrystalline quartz (SiO2)

Unidentifiable Rock Fragment

Chert (specifically Jasper or Flint)

Cryptocrystalline Quartz (SiO2)

Polished green stone, likely serpentine or nephrite jade

Serpentine-group minerals (commonly antigorite/lizardite) or nephrite, a fibrous tremolite–actinolite aggregate

Tumbled purple gemstone, likely amethyst

Amethyst, purple variety of quartz (SiO₂)

Tumbled yellow calcite (probable)

Calcite — calcium carbonate, CaCO₃

Blue aventurine or dyed blue chalcedony (tumbled stone)

Likely microcrystalline quartz, SiO₂; exact identification requires testing

Likely tumbled yellow calcite or quartz

Uncertain; possibly calcite (CaCO₃) or iron-stained quartz (SiO₂)

Polished labradorite heart pendant

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

Tumbled translucent quartz or chalcedony fragment

Silicon dioxide, SiO₂; likely quartz/chalcedony

Tumbled quartz (likely clear quartz)

Quartz, silicon dioxide (SiO₂)

Polished greenstone (likely serpentinite or green granite)

Probably serpentinized ultramafic rock, chiefly serpentine-group minerals; exact identification requires testing

Tumbled yellow chalcedony (likely yellow jasper or silicified material)

Microcrystalline quartz, SiO₂; precise identification requires testing

Chert

Silicon dioxide (SiO2)

Tumbled quartz bead bracelet

Quartz (SiO₂), likely milky or rose quartz

Granodiorite

Granodiorite

Dyed, polished stone—possibly rhodonite or pink jasper

Likely rhodonite (MnSiO₃) or manganese-rich jasper; exact identification requires testing

Dyed red crystal aggregate, likely quartz or salt

Uncertain; possibly dyed quartz (SiO₂) or halite (NaCl)

Quartzite

Metamorphic Quartzite (SiO2)

Natural Pearl

Calcium carbonate (primarily Aragonite and Conchiolin), CaCO3

Polished black stone, likely shungite

Shungite; carbon-rich mineraloid composed mainly of amorphous carbon, with silica and other minerals

Likely clear quartz pebble or glassy quartz fragment

Quartz (silicon dioxide, SiO₂)

Likely yellow quartz gemstone ring

Quartz (SiO₂), possibly heat-treated citrine or lemon quartz; metal setting appears to be brass/gold-colored alloy

Chert / Flint

Silicon dioxide (SiO2)

Tumbled quartz (likely milky/rose quartz)

Quartz, silicon dioxide (SiO₂)

Tumbled rose quartz

Quartz, silicon dioxide (SiO₂), pink variety

Chipped Glass/Plastic Fragment

Silicon dioxide (SiO2) for glass (amorphous) or various polymer compounds for plastic

Polished quartz crystal point

Quartz (silicon dioxide, SiO₂)

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Green cabochon, likely dyed or imitation material

Undetermined; the image is insufficient to identify a mineral species

Polished orbicular granite (likely orbicular diorite)

Orbicular granitoid; chiefly quartz, feldspar, and dark amphibole/biotite