Man Made Material (Metal)

Gemstone rings (stones not reliably identifiable)

The pale stone may be quartz or another translucent gem; the red stone may be ruby, garnet, or synthetic corundum. Image detail is insufficient for identification.

Flint (chert)

Microcrystalline quartz (SiO₂), a variety of chert

Red gemstone ring, possibly synthetic ruby or red glass

Unidentified red stone; ruby is corundum (Al₂O₃), but the image cannot confirm its identity

Coquina

Bioclastic Limestone

Pumice

Pumice (Vesicular volcanic glass / Rhyolite or Trachyte)

Likely flint (chert) fragment

Chert, microcrystalline quartz (SiO₂)

Limonite (Iron Stone/Iron Ore)

FeO(OH)·nH2O (Hydrous ferric oxide)

Clear faceted gemstone in an ornate ring (likely quartz or glass imitation)

Unidentified colorless faceted stone; visual identification is inconclusive

Red gemstone ring, likely synthetic ruby or garnet

Ruby: corundum (Al₂O₃); possible alternative: almandine garnet (Fe₃Al₂(SiO₄)₃)

Titanium Quartz (Aura Quartz)

Silicon Dioxide (SiO2) treated with Titanium

Sandstone

Arenite

Vesicular basalt (scoria-like volcanic rock)

Vesicular basalt; predominantly plagioclase, pyroxene, and volcanic glass, with possible iron oxides

Chert (likely flint)

Microcrystalline quartz (SiO₂), variety chert; flint is a dark chert variety

Iron-rich rock fragment (likely limonite/goethite weathering material)

Hydrated iron oxides, chiefly goethite (α-FeO(OH)) and/or limonite (variable mixture)

Coquina

Biogenic Limestone (Calcium Carbonate, CaCO3)

Tumbled yellow chalcedony (possibly citrine or pale agate)

Chalcedony, microcrystalline quartz (SiO₂); exact variety cannot be confirmed visually

Red cabochon gemstone ring, likely synthetic ruby or red glass

Possibly corundum (Al₂O₃, chromium-colored); identity cannot be confirmed from the image

Tumbled milky chalcedony (likely common opal or quartz-rich chalcedony)

Chalcedony, microcrystalline SiO₂; identification is uncertain from the photo

Biotite-rich mica schist

Mica schist, dominated by biotite mica (K(Mg,Fe)₃AlSi₃O₁₀(F,OH)₂), with probable quartz and feldspar

Slag (Industrial Byproduct)

Ferrous/Non-ferrous Silicate

Carved green jade pendant or ornament

Likely jadeite (NaAlSi₂O₆) or nephrite (Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂); image alone cannot distinguish them

Diamond-set gold ring

Diamond (crystalline carbon, C); mounted in a gold alloy setting

Silicon Carbide

Silicon Carbide (Moissanite / Carborundum), SiC

Clear crystal-bead bracelet, possibly quartz

Unidentified transparent mineral beads; quartz (SiO₂) is one possibility

Red agate bead (likely dyed or treated)

Agate, a microcrystalline variety of quartz; SiO₂

Red-orange sunstone (likely aventurine feldspar) bead bracelet

Feldspar, commonly oligoclase or labradorite with copper inclusions; composition varies by source

Chromite

Chromite (FeCr2O4)

Faceted gemstone ring, likely smoky quartz or garnet in a metal setting

Not determinable from the photograph; possible quartz (SiO₂) or garnet-group silicate

Green agate (likely dyed), used as jewelry beads

Microcrystalline quartz, SiO₂ (chalcedony; agate variety)

Brown chert (flint)

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

Slate

Metamorphic Pelitic Rock

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

Chert or Jasper

Microcrystalline Quartz (SiO2)

Quartz Vein in Siltstone

SiO2 (Quartz) on clastic sedimentary matrix

Gemstone butterfly brooch/pendant

Likely faceted pink tourmaline or synthetic spinel in gilt metal; exact identification requires testing

Quartz-rich breccia or quartz vein fragment

Silica, primarily quartz (SiO₂), with possible chlorite, feldspar, or iron-oxide inclusions

Engraved purple stone cabochon, possibly amethyst

Unconfirmed; if amethyst, quartz (SiO₂)

Polished stromatolite (likely fossilized microbial mat)

Fossil stromatolite; chiefly microcrystalline quartz (SiO₂), commonly replacing carbonate

White flint (chert)

Microcrystalline quartz, SiO₂

Exposed aggregate concrete (stone-chip surface)

Portland-cement concrete containing natural aggregate; not a natural rock

Red jasper

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

Faceted yellow-brown gemstone ring

Likely citrine (quartz, SiO₂); the image alone cannot confirm the stone or any treatments.