Man Made Byproduct (Non Geological)

Borosilicate Glass (Manufactured)

SiO2 + B2O3 (Silicon dioxide and Boron trioxide)

Unidentified polished dark gemstone cabochon

Possibly hematite, obsidian, jet, or dark agate; image insufficient for a definitive identification

Polished brecciated jasper pendant

Jasper, an opaque microcrystalline variety of chalcedony (mostly SiO₂), with iron-oxide staining and likely brecciation

Black glassy volcanic rock, likely scoria or obsidian

Vesicular basaltic scoria (probable); possibly dark obsidian

Polished rutilated quartz cabochon

Quartz (SiO₂) with rutile inclusions (TiO₂)

Faceted amber-colored gemstone, possibly citrine

Unidentified transparent gem; citrine is quartz (SiO₂), but the image alone cannot confirm the material

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

Yellow faceted gemstone, likely citrine or synthetic glass

Citrine (quartz, SiO₂) is the leading natural possibility; visual identification is uncertain from the photograph

Limestone

Calcium Carbonate (CaCO3)

Granite

Felsic intrusive igneous rock

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Malaysian 50 Sen Coin

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

Pale green aventurine (likely quartz) sphere

Quartz, SiO₂; possibly pale green aventurine, with color from inclusions or treatment

Milky quartz

Quartz (silicon dioxide, SiO₂)

Likely tumbled epidote-bearing rock or green jasper

Epidote-group silicate, possibly in a jasper or serpentinite matrix

Crushed Stone / Gravel

Aggregatus saxum (variable mineral composition)

Sandstone

Sandstone (Quartz-rich Arenite / SiO2)

Chert (Flint)

Silicon Dioxide (SiO2)

Concrete-like aggregate surface with embedded rock fragments

Anthropogenic concrete or exposed aggregate; not a natural rock specimen

Granite

Granite (plutonic igneous rock)

Sandstone

Arenite

Small metallic-gold mineral fragment, possibly pyrite

Pyrite (FeS₂), if confirmed

Carnelian cabochon pendant

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

Bog Iron / Limonite Concretion

Goethite/Limonite mixture (FeO(OH)·nH2O)

Abbey Bominable (Monster High character)

Anthropomorphic Yeti / Digital Animation

Chert / Flint

Microcrystalline Quartz (SiO2)

Tumbled brown chalcedony (likely jasper or agate)

Microcrystalline quartz, SiO₂; chalcedony with iron-oxide staining

Botryoidal chalcedony with iron-oxide staining

Microcrystalline quartz (SiO₂), likely iron-oxide-bearing chalcedony

Likely gold-colored metal ring with a possible gemstone

Uncertain; possibly gold alloy (Au) with a small quartz or glass-like setting

Weathered iron-stained stone, likely graywacke or altered sandstone

Indeterminate lithic fragment; probable quartz-rich sandstone/graywacke with iron-oxide staining

Quartz-rich rock, possibly milky quartz

Quartz (SiO₂); exact specimen identification is uncertain from the photograph

Chert

Microcrystalline Quartz (SiO2)

Likely slag or metallic industrial byproduct

Unidentified iron-rich ferrous slag; possibly magnetite-bearing slag

Chert (flint) fragment

Microcrystalline quartz (SiO₂), commonly called chert; “flint” is a variety of chert

Jasper

Silicon dioxide (Microcrystalline Quartz, SiO2)

N/A (Non-Geological Specimen)

Likely polished dark stone or mineral specimen (unidentifiable from image)

Undetermined; possibly dark quartz-rich material, basalt, or obsidian

Chert (specifically Flint)

Chert (SiO2)

Yellow chalcedony (likely polished/tumbled pieces)

Microcrystalline quartz, SiO₂; commonly called yellow jasper or silicified limestone depending on exact texture

Chert (Cherty Shale / Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)