Synthetic (Ceramic)

Chert (Nodular Chert)

Microcrystalline Quartz (SiO2)

Milky Quartz

Quartz (Silicon Dioxide, SiO2)

Quartzite

Quartzite (primarily SiO2)

Clear Quartz (faceted) / Diamond Simulant

Silicon Dioxide (SiO2) / Cubic Zirconia (ZrO2)

Blue gemstone ring (likely sapphire)

Likely corundum, Al₂O₃; the dark, reflective appearance may also indicate a treated or synthetic stone.

Likely weathered pebble or mineral fragment

Indeterminate; possibly quartz-rich stone, iron-stained feldspar, or a small chert fragment

Tumbled blue-green stone, possibly aquamarine or chalcedony

Indeterminate from image; possibilities include beryl (Be₃Al₂Si₆O₁₈) or cryptocrystalline quartz (SiO₂)

Cubic Zirconia

Zirconium dioxide (ZrO2)

Lapis Lazuli (Tumbled Stone)

Na6Ca2(Al6Si6O24)(SO4,S,Cl)2 (predominantly Lazurite)

Silicon Carbide (Carborundum)

Silicon Carbide (SiC)

Diamond or Cubic Zirconia

Carbon (diamond) or Zirconium dioxide (cubic zirconia)

Faceted colorless gemstone, likely glass or diamond imitation

Unidentified; possibly diamond (carbon, C) or cubic zirconia (zirconium dioxide, ZrO₂)

Aura Quartz

Silicon Dioxide (SiO2) with Titanium/Metal vapor coating

Sapphire

Corundum (Al2O3)

Dalmatian Stone

Dalmatian Jasper (a misnomer) / Perthitic Feldspar Rock

Diamond (Faceted Colorless)

Diamond (Pure Carbon, C)

Diamond (or Cubic Zirconia simulant)

C (Carbon) or ZrO2 (Zirconium Dioxide)

Opalite

Opalescent Glass (SiO2 + coloring agents)

Weathered iron-rich rock, possibly laterite or ironstone

Goethite–hematite-rich ferruginous rock; uncertain without testing

Blue cabochon gemstone, likely synthetic glass or dyed stone

Indeterminate from image; possible glass, synthetic spinel, sodalite, or lapis lazuli

Clear faceted gemstone, likely synthetic cubic zirconia

Cubic zirconia (zirconium dioxide, ZrO₂); visual identification is not definitive and diamond or synthetic moissanite are alternatives

Tumbled milky quartz pebble

Quartz (silicon dioxide, SiO₂), likely milky quartz

Weathered brown rock, possibly iron-rich sandstone or limonite

Tentative: ferruginous sandstone (quartz with iron oxides) or limonite/goethite-rich material

Likely foliated metamorphic rock (quartz-mica schist or gneiss)

Quartz–feldspar–mica metamorphic rock; exact identification requires a fresh surface and tests

Small weathered pebble, possibly limestone

Indeterminate carbonate-rich rock; likely calcite-bearing limestone

Ferruginous Sandstone (Ironstone)

Arenite with Limonite/Goethite cement

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

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

Faceted transparent gemstone, likely glass or cubic zirconia

Uncertain from image; possible cubic zirconia (zirconium dioxide, ZrO₂) or glass imitation

Mounted clear gemstone, likely cubic zirconia

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

Emerald in Matrix

Beryl (Be3Al2Si6O18) with Chromium/Vanadium impurities

Smoky Quartz

Silicon Dioxide (SiO2)

Faceted Diamond or Cubic Zirconia

Carbon (C) for Diamond; Zirconium dioxide (ZrO2) for CZ

Cubic Zirconia (as a jewelry specimen)

Zirconium dioxide (ZrO2)

Tumbled black stone, likely basalt

Basalt; fine-grained plagioclase–pyroxene rock, possibly with magnetite

Polished pink feldspar pebble

Orthoclase or microcline feldspar, KAlSi₃O₈

Likely raw blue kyanite specimens

Kyanite, Al₂SiO₅

Quartzite

Quartzite (primarily SiO2)

Milky Quartz

Silicon Dioxide (SiO2)

Lepidolite

K(Li,Al)3(Al,Si,Rb)4O10(F,OH)2

Brachiopod Fossil in Shale

Phylum Brachiopoda (often species of Order Spiriferida or Rhynchonellida)

Quartzite

Quartzite (primarily SiO2)

Blue sapphire (likely synthetic or treated corundum)

Corundum, aluminum oxide (Al₂O₃), blue from iron and titanium impurities