Mineraloid (Human Made Geological Specimen)

Blue gemstone ring, likely sapphire

Corundum, Al₂O₃ (probable blue sapphire); surrounding stones may be diamonds or simulants

Diamond-set gold ring (stone identity uncertain)

Possible diamond (crystalline carbon, C); metal setting appears gold-colored

Likely quartz crystal sphere

Quartz (silicon dioxide, SiO₂), possibly included or coated quartz

Blue cabochon gemstone ring

Likely blue turquoise, glass-filled sapphire, or blue spinel; exact identification requires testing

Tumbled clear quartz (rock crystal)

Quartz — silicon dioxide (SiO₂)

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂), cryptocrystalline to microcrystalline variety

Green glassy slag or manufactured glass bead

Noncrystalline silicate glass; likely industrial glass/slag, not a true mineral

Tumbled blue stone, likely blue calcite

Calcite (CaCO₃), blue variety; identification is provisional from the image

Fulgurite

Fulgurite (Lechatelierite-rich fused silica)

Tumbled milky quartz

Quartz, silicon dioxide (SiO₂)

Goldstone (blue/black aventurine glass)

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

Polished agate or chalcedony nodule

Microcrystalline quartz (SiO₂), likely agate/chalcedony

Chert

Silicon dioxide (SiO2)

Granodiorite

Granodiorite

Chert (variations include Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Yellow chalcedony (likely lemon agate or yellow jasper)

Microcrystalline quartz, SiO₂; possibly iron-bearing jasper or chrysoprase-like chalcedony

Red garnet bead

Likely almandine–pyrope garnet, garnet-group silicate (approximately Fe₃Al₂Si₃O₁₂–Mg₃Al₂Si₃O₁₂)

Rose quartz bangle

Quartz, silicon dioxide (SiO₂), commonly colored by trace elements and inclusions

Tumbled quartzite pebble (likely)

Quartz-rich quartzite; mainly SiO₂

Natural Pearl

Calcium carbonate (primarily Aragonite and Conchiolin), CaCO3

Chert

Microcrystalline quartz (SiO2)

Polished tiger’s-eye jasper (likely brecciated jasper)

Quartz-rich microcrystalline silica; mainly chalcedony/quartz (SiO₂) with iron-oxide pigments

Engraved polished dark stone (likely slate or basalt)

Probable fine-grained slate (microcrystalline phyllosilicates), possibly basalt; exact identification requires testing

Concrete fragment with Aggregate

Anthropogenic Concrete with Calcarious and Siliceous Aggregate

Cullet (Slag Glass)

Amorphous Silica (SiO2) with various metal oxide colorants

Tumbled yellow calcite (probable)

Calcite — calcium carbonate, CaCO₃

Likely tumbled green mineral (possibly serpentine or aventurine)

Indeterminate; possibilities include serpentine-group minerals, nephrite, or green aventurine quartz

Chert (Nodule)

Microcrystalline Quartz (SiO2)

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Dark metallic-looking mineral specimen, possibly magnetite

Magnetite (Fe₃O₄), tentative identification

Likely dyed or painted stone

Unidentified natural rock; vivid purple, orange, and pink coloration appears to be a surface coating or pigment, so the underlying rock cannot be reliably identified from the image.

Dyed mineral cluster, likely calcite or aragonite

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

Tumbled metallic-gray stone, likely hematite or magnetite

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

Small tumbled stone, likely quartz-rich pebble

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

Chert

Silicon Dioxide (SiO2)

Likely tumbled yellow calcite or quartz

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

Terrazzo flooring containing marble aggregate

Marble (recrystallized calcite, CaCO₃) aggregate in cementitious terrazzo

Likely polished greenstone or serpentine inlay

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

Blue aventurine or dyed blue chalcedony (tumbled stone)

Likely microcrystalline quartz, SiO₂; exact identification requires testing

Polished labradorite heart pendant

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

Unidentifiable Rock Fragment

Red jasper (likely)

Jasper, an opaque microcrystalline variety of quartz (SiO₂), colored red by iron oxides