Man Made Material

Quartz-rich gravel fragment

Quartz (silicon dioxide, SiO₂), possibly with feldspar or carbonate inclusions

Likely polished leopard-skin jasper or brecciated jasper

Jasper, an opaque microcrystalline variety of quartz (SiO₂), with iron-oxide and other mineral inclusions; exact variety cannot be confirmed from the image alone

Rough Diamond

Diamond (pure Carbon, C)

Quartzite

Metamorphosed Quartz Sandstone

Tumbled chalcedony (likely blue-gray agate)

Cryptocrystalline quartz, SiO₂; chalcedony/agate variety

Gneiss

Gneiss (a rock type, not a specific mineral with a formula)

Weathered sandstone fragment

Sandstone, primarily quartz (SiO₂) with feldspar and iron-oxide cement

Colorless faceted gemstone, likely cubic zirconia

Cubic zirconia (synthetic ZrO₂), possibly glass or quartz

Pearl

Aragonite (CaCO3) with Conchiolin

Pink Marble

Recrystallized Limestone (Calcium Carbonate, CaCO3)

Chert / Flint

Microcrystalline quartz (SiO2)

Chalk

Micrite (primarily Calcium Carbonate, CaCO3)

Likely blue glass or synthetic gemstone jewelry

Uncertain; possibly synthetic spinel, cubic zirconia, or blue glass

Sandstone

Clastic Sedimentary Rock

Polished hematite-rich ironstone

Hematite (Fe₂O₃), likely mixed with magnetite and iron-rich jasper

Green cabochon gemstone pendant, likely turquoise or dyed green turquoise

Probably turquoise, CuAl₆(PO₄)₄(OH)₈·4H₂O; exact identification requires testing

Polished/tumbled multicolored stone, possibly jasper

Likely opaque microcrystalline quartz (chalcedony/jasper); exact identification is uncertain because the image is out of focus

Unidentified weathered rock fragments

Likely mixed silicate rocks; specific identification requires testing

Red jasper-like chalcedony pebble

Microcrystalline quartz (SiO₂), likely iron-stained chalcedony/jasper

Quartz (possibly milky quartz or quartz with inclusions)

SiO2 (Silicon Dioxide)

Tumbled quartz pebble

Quartz (silicon dioxide, SiO₂)

Fossil-bearing sedimentary rock, possibly fossil wood or bone

Indeterminate silicified/carbonate fossil in sandstone or mudstone

Milky quartz

Quartz (silicon dioxide, SiO₂)

Chert (Septarian Nodules-like)

Silicon dioxide (SiO2)

Granite (Pegmatitic)

Phaneritic Felsic Igneous Rock

Chert (specifically White Chert or Flint)

Microcrystalline or Cryptocrystalline Quartz (SiO2)

Polished green aventurine

Quartzite dominated by quartz (SiO₂), colored by fuchsite mica and/or iron-bearing inclusions

Chert

Microcrystalline Quartz (SiO2)

Chert Breccia

Brecciated Chert (Microcrystalline Silica, SiO2)

Dumortierite in Quartz

Dumortierite (Al6O3(BO3)(SiO4)3) with Quartz (SiO2)

Quartz (likely milky quartz or a stained variety)

Silicon Dioxide (SiO₂)

Quartz

Silicon Dioxide (SiO₂)

Diamond

Carbon (C)

Limestone

Sedimentary Calcium Carbonate (CaCO3)

Quartzite

Quartzite (SiO2)

Pallasite Meteorite

Pallasite (Stony-Iron Meteorite)

Pearl (with Peridot)

Calcium carbonate (CaCO3) + Conchiolin; Peridot: Magnesium iron silicate (Mg, Fe)2SiO4

Iron meteorite fragment (likely weathered meteorite)

Fe–Ni metal, commonly kamacite with taenite; possible stony-iron or iron-oxide fusion crust

Quartz-rich rock, likely chert or chalcedony

Microcrystalline silica (SiO₂), possibly quartz/chalcedony

Pink chalcedony (likely rough agate/chalcedony)

Microcrystalline quartz, SiO₂; chalcedony variety, possibly iron-bearing

Weathered chert or jasper nodule

Microcrystalline quartz (SiO₂), likely chalcedony/jasper with iron-oxide staining

Polished chert or jasper cobble

Microcrystalline quartz (SiO₂), commonly called chert; iron-oxide-bearing varieties are jasper