Synthetic (Man Made Material Mimicking Natural Stone)

Mounted clear gemstone, likely cubic zirconia

Cubic zirconia (zirconium dioxide, ZrO₂), synthetic; exact stone cannot be confirmed from the image

Carborundum (Silicon Carbide)

Silicon Carbide (SiC) / Moissanite (natural form)

Emerald (green gemstone in a jewelry setting)

Beryl, Be₃Al₂(SiO₃)₆; green color commonly from chromium and/or vanadium

Cubic Zirconia (Faceted)

Zirconium dioxide (ZrO2)

Green faceted gemstone, likely emerald or synthetic emerald

Beryl, Be₃Al₂Si₆O₁₈, colored green by chromium and/or vanadium; identity cannot be confirmed visually

Sea Glass

Man-made vitreous material (silica-based glass)

Gastropod Internal Mold (Steinkern)

Class Gastropoda fossil mold (Phylum Mollusca)

Faceted purple-blue beads, likely synthetic glass or treated gemstone

Indeterminate; possible synthetic corundum, synthetic spinel, or dyed quartz (SiO₂)

Blue glassy tumbled stone, likely blue chalcedony or slag glass

Chalcedony (microcrystalline SiO₂), possibly man-made blue glass

Aura Quartz (Pink/Rose Aura Quartz)

Silicon Dioxide (SiO2) bonded with Platinum and/or Silver

Clear quartz fragment

Quartz (silicon dioxide, SiO₂)

Libyan Desert Glass

Libyan Desert Glass (SiO2 with trace elements)

Fossiliferous limestone with colonial coral

Calcite (CaCO₃) limestone containing fossil tabulate or rugose coral colonies

Amethyst (faceted gemstone)

Quartz, silicon dioxide (SiO₂), purple variety colored mainly by iron-related defects

Milky quartz (rough fragment)

Quartz, silicon dioxide (SiO₂)

Exposed aggregate concrete (stone-chip surface)

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

Sandstone (with concrete/human-made layer)

Clastic Sedimentary Rock (primarily Quartz/Feldspar grains)

Sandstone Concretion

Limonitic Sandstone Concretion

Granite with Cupules / Bedrock Mortars

Granite (felsic intrusive plutonic rock)

Diamond (or Cut Gemstone / Cubic Zirconia)

Carbon (C)

Tumbled hematite

Hematite (Fe₂O₃), commonly sold as “magnetic hematite” when synthetic or magnetized

Dyed Quartz Geode

Silicon Dioxide (SiO2) with artificial pigment

Decorative opal-like turtle mosaic

Likely imitation or assembled opal material; exact stones cannot be confirmed visually

Colorless faceted gemstone, likely quartz

Quartz (SiO₂), probably rock crystal; exact identification is uncertain from the strongly backlit image

Dalmatian Stone

Dalmatian Jasper (a misnomer for an Aplite with Arfvedsonite spots)

Blue gemstone ring, likely lapis lazuli

Lapis lazuli: lazurite-rich metamorphic rock, chiefly (Na,Ca)8(AlSiO4)6(S,SO)2, commonly with calcite and pyrite

Tumbled quartz pebble

Quartz, silicon dioxide (SiO₂), likely milky quartz

Cubic Zirconia

Zirconium Dioxide (ZrO2)

Tumbled cream-colored pebble

Likely quartz-rich sandstone or limestone; exact identification requires testing

Diamond

Native Carbon (C)

Obsidian (likely black volcanic glass)

Obsidian; primarily amorphous volcanic silica glass, approximately SiO₂-rich rhyolitic composition

Cubic Zirconia (as used in jewelry setting)

Zirconium dioxide (ZrO2)

Blue Slag Glass

Man-made Silicon Dioxide (Amorphous)

Red-orange jasper pebble (tentative)

Microcrystalline quartz, SiO₂, colored mainly by iron oxides

Red/pink faceted gemstone, likely synthetic ruby or red glass

Corundum (Al₂O₃) if ruby; identity cannot be confirmed visually

Pearls (likely freshwater cultured pearls)

Pearl: nacre, primarily aragonite (CaCO₃) with conchiolin

Hematite bead bracelet

Hematite (iron(III) oxide, Fe₂O₃), likely polished magnetic hematite or hematite-coated beads

Blue glassy fragment among beach gravel

Likely cobalt-blue man-made glass; not a natural mineral specimen

Concrete with Aggregate

Composite construction material; primary matrix is Calcium Silicate Hydrate (C-S-H)

Faceted golden beryl (likely heliodor)

Beryl, Be₃Al₂Si₆O₁₈; yellow color from iron impurities

Likely silicon carbide (carborundum)

Synthetic silicon carbide (SiC), likely blue-green crystalline grit

Goldstone (aventurine glass)

Synthetic copper-bearing soda-lime glass; commonly sold as red goldstone