Man Made (Synthetic Rock)

Blue cabochon gemstone, likely blue sapphire

Corundum (Al₂O₃), colored blue by trace iron and titanium

Sapphire

Corundum (Al2O3)

Banded calcite (likely polished limestone/marble fragment)

Calcite, CaCO₃; probable banded calcitic marble

Basalt

Basalt

Sandstone

Arenite (primarily SiO2)

Sandstone

Sedimentary Clastic Rock (Quartzose Sandstone)

Red jasper (likely)

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

Pink faceted gemstone, likely synthetic or treated quartz

Quartz, silicon dioxide (SiO₂); exact identity cannot be confirmed from the image

Clear quartz sphere

Quartz (silicon dioxide, SiO₂), likely rock crystal or low-grade milky quartz

Chert (Flint)

SiO2 (Microcrystalline Quartz)

Blue-green faceted pendant stone

Undetermined; possibly synthetic glass or a blue-green gemstone such as topaz or quartz

Sandstone (Quartz Arenite)

Sandstone (dominated by SiO2 quartz grains)

Emerald

Beryl (Be₃Al₂Si₆O₁₈), colored green by chromium and/or vanadium

Amber (and Cubic Zirconia)

Fossilized Tree Resin

Citrine

Silicon Dioxide (SiO2)

Gold ring with a clear faceted gemstone

Likely diamond (carbon, C); the photograph is insufficient to confirm the stone or metal

Granite

Felsic intrusive igneous rock

Granite

Phaneritic Felsic Intrusive Igneous Rock

Limestone

Calcareous sedimentary rock (CaCO3)

Granite

Granite (Phaneritic Quartz-Feldspar intrusive rock)

Quartzite

Metamorphic Quartzite (SiO2)

Bivalve Fossil (Shell Fragment)

Class Bivalvia (Calcium Carbonate - CaCO3)

Black-and-white agate geode pendant

Agate (microcrystalline quartz, SiO₂), likely a hollow geode slice with chalcedony and drusy quartz

Red gemstone ring, possibly synthetic ruby or red glass

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

Chert Arrowhead

Cryptocrystalline Quartz (SiO2)

Laterite

Laterite (Fe2O3 and Al2O3-rich residual rock)

Small blue cut gemstone, possibly synthetic spinel or glass; species cannot be determined from the photo

Undetermined; blue synthetic spinel (MgAl₂O₄) is one possibility

Coquina

Bioclastic Limestone (composed primarily of CaCO3)

Red gemstone ring; likely synthetic ruby or red glass

Undetermined from the image; ruby is corundum (Al₂O₃), while red glass is amorphous silicate

Unakite

Altered Granite (Epidotized Granite)

Coquina

Biogenic Limestone (CaCO3)

Sandstone

Arenite (composed primarily of SiO2)

Sandstone

Sandstone (composed predominantly of Quartz, SiO2, with Feldspar and Clay minerals)

Chert (often called Flint)

Chert (Microcrystalline or cryptocrystalline Silica, SiO2)

Diamond (Heart Cut)

Carbon (C)

Smoky Quartz

Silicon Dioxide (SiO2)

Ruby

Corundum (Al2O3) with Chromium traces

Faceted clear gemstone in a metal setting

Unidentified transparent faceted gem; possibilities include quartz (SiO₂), topaz (Al₂SiO₄(F,OH)₂), or glass—the image is insufficient for identification.

Blue-green cut gemstone, possibly aquamarine

Unconfirmed; aquamarine is blue-green beryl, Be₃Al₂Si₆O₁₈

Blue gemstone ring, likely blue topaz or synthetic blue spinel

Likely topaz (Al₂SiO₄(F,OH)₂) or synthetic spinel (MgAl₂O₄); identification is uncertain from the image

Nickel coin (U.S. currency)

Cupronickel (75% Copper, 25% Nickel alloy)

Fossil coral

Fossilized colonial coral, likely rugose or tabulate coral preserved in limestone