Man Made Material (Metal)

Pumice

Pumice (Vesicular volcanic glass / Rhyolite or Trachyte)

Biotite-rich mica schist

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

Red cabochon gemstone ring, likely synthetic ruby or red glass

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

Gemstone butterfly brooch/pendant

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

Ruby in Matrix

Corundum (Al2O3)

Coquina

Bioclastic Limestone

Diamond

Carbon (C)

Sandstone

Arenite

Chromite

Chromite (FeCr2O4)

Coquina

Biogenic Limestone (Calcium Carbonate, CaCO3)

Yellow faceted gemstone earrings, likely citrine or yellow beryl

Citrine: quartz, SiO₂; possible yellow beryl: Be₃Al₂Si₆O₁₈

Green cabochon gemstone pendant

Indeterminate; likely dyed green turquoise, chrysoprase, or opaque beryl set with blue/clear accent stones

Faceted yellow-brown gemstone ring

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

Quartz Vein in Siltstone

SiO2 (Quartz) on clastic sedimentary matrix

Slate

Metamorphic Pelitic Rock

Chert (Jasper/Flint variety)

Silicon Dioxide (SiO2)

Chert or Jasper

Microcrystalline Quartz (SiO2)

Quartz-rich breccia or quartz vein fragment

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

Ferrochrome Slag

Anthropogenic silicate/oxide glass (Complex silicate matrix with Cr-Fe-Si inclusions)

White pebbles (rock material not identifiable from the image)

Undetermined; the smooth, pale pieces could be quartz, quartzite, or another light-colored rock

Cabochon gemstone ring, likely smoky quartz or tourmaline

Unconfirmed quartz (SiO₂) or brown tourmaline (dravite); visual identification is inconclusive

Likely quartz cabochon in a ring

Quartz (SiO₂), possibly clear or milky quartz; identification is uncertain from the photograph

Brown weathered river pebble

Indeterminate lithology; likely ferruginous sandstone, mudstone, or weathered volcanic rock

Exposed aggregate concrete (stone-chip surface)

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

Polished stromatolite (likely fossilized microbial mat)

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

Tiger Shark Fossil Tooth

Galeocerdo cuvier (fossilized)

Diamond (as set in a gold ring)

Carbon (C)

Blue chalcedony cabochon (probable)

Chalcedony, a cryptocrystalline variety of quartz; silicon dioxide, SiO₂

Biotite schist

Mica schist, composed mainly of biotite mica and quartz with feldspar and iron oxides

Chert (Flint)

Silicon Dioxide (SiO2)

Limpets Shell / Fossil Specimen

Patellogastropoda (Class)

Chert (specifically Tan/Gray Chert)

Microcrystalline quartz (SiO2)

Chert (varietal: Flint/Jasper)

Silicon Dioxide (SiO2)

Probable metallic meteorite fragment

Unclassified iron meteorite candidate, chiefly kamacite (α-Fe–Ni alloy)

Chert (specifically Flint Arrowhead)

Silicon dioxide (SiO2) - Microcrystalline Quartz

Jasper / Chert (Red)

Cryptocrystalline quartz (SiO2)

Nugget of Native Silver

Native Silver (Ag)

Coquina (Fossiliferous Limestone)

Biogenic Limestone (Calcium Carbonate, CaCO3)

Iron-stained quartz vein in altered host rock

Quartz (SiO₂) with iron oxides/hydroxides, likely hematite and goethite; host rock uncertain from the image

Granite

Felsic intrusive igneous rock

Unidentified gray stone/concrete-like fragment

Indeterminate; likely a fine-grained carbonate or cementitious geological fragment

Stony Meteorite (Chondrite)

Ordinary Chondrite (L or H type)