Very Sturdy Costume Piece All jewelry metal has been tested regardless of hallmarks, markings, signatures, etc. using ThermoScientific™ Niton™ XL2 Analyzer (Energy Dispersive X-ray Fluorescence). We do not have equipment to test cultured vs. natural pearls. We assume that they are cultured. Faux pearls are noted when found. Cultured pearls and natural pearls are both real pearls. Natural pearls are uncommon and requires specialized gemological equipment to determine authenticity. Most stones are tested Presidium® Gem Tester II when possible. Where the jewelry settings allow diamonds and diamond simulants are tested using a Gemoro Testerossa testing wand. If we can determine synthetic and artificial gems, it is noted. Gemstones without the designation “lab” or “synthetic” are unknown to us and are assumed to be lab created/synthetic. There are many names for varieties of Quartz Chalcedony, some are trade names or more common names, these are often represented as types of Jasper or Agate. Quartz as a mineral is abundant and represents the majority of gemstones we list, however please note Quartz (Particularly popular stones like Amethyst, Ametrine and Citrine) can also be Lab-created/synthetic, we do not distinguish between natural or lab created quartzes.or we do not distinguish between natural and treated turquoise.