Mineraloid (Human Made Geological Specimen)

Chert Arrowhead (Jasper)

Chert (Cryptocrystalline Quartz, SiO2)

Chert (and/or Flint)

Microcrystalline Quartz (SiO2)

Chert

Microcrystalline Quartz (SiO2)

Tumbled quartz (likely milky quartz)

Quartz — silicon dioxide (SiO₂)

Tumbled pale limestone or calcite-rich stone

Limestone, chiefly calcite (CaCO₃); exact identification is uncertain from the photograph

Chert (Jasper variation)

Microcrystalline Quartz (SiO2)

Riverstone (Sandstone Pebble)

Arenite (SiO2 with various lithic fragments)

Chert (flint)

Microcrystalline quartz (SiO₂), commonly called chert; brown varieties may be termed brown flint

Chert (or Flint)

Chert (cryptocrystalline quartz), SiO2

Tumbled quartz-rich rock, possibly calcite or sandstone

Indeterminate from photograph; likely microcrystalline quartz (SiO₂) or calcite (CaCO₃)

White chalcedony cabochon ring

Chalcedony (microcrystalline quartz, SiO₂), likely white quartz variety

Blue apatite or dyed blue stone (likely apatite)

Apatite, Ca5(PO4)3(F,Cl,OH); exact identification is uncertain from the photograph

Flaked stone projectile point

Likely worked chert or fine-grained silicified shale; exact lithology cannot be confirmed from the image

Blue Goldstone

Aventurine Glass

Metal Alloy (Likely Pewter or Sterling Silver)

Not a natural geological specimen; composed of refined metals. If pewter, it's a tin-based alloy. If sterling silver, it's 92.5% silver and 7.5% other metals (usually copper).

White quartz pebble (likely milky quartz)

Quartz, silicon dioxide (SiO₂)

Chert (and/or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Chert (specifically White Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Likely polished dark stone (identity uncertain)

Undetermined; possibly polished basalt, chert, or another dark silicate rock

Chert (Flint variety)

Chert (Microcrystalline or Cryptocrystalline Quartz), SiO2

Flint or chert

Microcrystalline quartz (SiO₂), commonly called flint when dark and nodular

Likely tumbled quartz or calcite pebble

Quartz (SiO₂) or calcite (CaCO₃); exact identification requires testing

Slag

Metallurgical by-product

Synthetic Resin Charm (Seal Shape)

Polymer Resin with plastic glitter / Polyethylene terephthalate glitters

Chert Arrowhead (Projectile Point)

Microcrystalline Quartz (Chert or Flint)

Cut gemstone ring, likely diamond

Diamond (carbon, C), faceted gemstone; exact stone identification is uncertain from the image

Faceted Quartz (Rock Crystal)

Crystalline Silicon Dioxide (SiO2)

Tumbled smoky quartz

Quartz (SiO₂), likely smoky variety

Faceted clear quartz (rock crystal), likely a cut imitation or low-grade gemstone

Quartz, silicon dioxide (SiO₂)

Dog (Sleeping)

Canis familiaris (or Canis lupus familiaris)

Painted beach pebble

Unidentified natural pebble; underlying lithology cannot be determined from the image

Tumbled light-green quartz, likely aventurine or prehnite

Quartz (SiO₂), possibly green aventurine; visual identification is uncertain

Black obsidian

Volcanic glass; predominantly rhyolitic silica glass (approximately 70–80% SiO₂)

Likely tumbled quartz or calcite fragment

Probably quartz (SiO₂) or calcite (CaCO₃)

Possible industrial slag or basaltic volcanic glass

Likely iron-rich vitreous slag; natural alternative: basaltic glass (tachylite)

Faceted colorless gemstone, likely cubic zirconia or diamond

Cubic zirconia (zirconium dioxide, ZrO₂) or diamond (carbon, C)

Gemstone ring, likely emerald and opal

Green beryl (Be₃Al₂Si₆O₁₈), with probable common opal (hydrated amorphous silica, SiO₂·nH₂O)

Unidentified translucent crystal/mineral fragment

Likely quartz (SiO₂), but visual identification is uncertain

Tumbled milky quartz (probable)

Quartz, silicon dioxide (SiO₂)

Tumbled quartz (likely milky or rose quartz)

Quartz, silicon dioxide (SiO₂)

Tumbled milky quartz

Quartz (silicon dioxide, SiO₂)

Opal

Hydrated Silica (SiO2·nH2O)