14k vs 18k gold adularescence alexandrite alexandrite engagement ring asterism beryl birthstones Brazilian paraiba cat's eye gem chrysoberyl Cleopatra jewelry collector gemstones collector stones Colombian emeralds color change garnet color change gemstone color change gemstones color change sapphire copper tourmaline copper-bearing tourmaline corundum cubic zirconia vs diamond diamond alternatives diamond simulants diamond vs moissanite diaspore dual color gems dual-color gem electric tourmaline emerald emerald by day ruby by night ethical diamonds feldspar jewelry fine gemstone care fine jewelry stones gemstone care gemstone colors gemstone comparison gemstone history gemstone investment gemstone lore gemstone optical effects gemstone symbolism gemstone transformations gemstone treatments gold karats green gemstones hackmanite high-end gemstones HPHT vs CVD diamonds jardin inclusions jewelry buying guide jewelry metals comparison June birthstone lab-created diamonds lab-grown diamonds labradorescence light effects in gemstones light reactive gemstones luxury gemstone jewelry magical gemstones metal choices in jewelry metamerism gems moissanite engagement rings moonstone moonstone glow Mozambique paraiba Mughal emeralds mystical gemstones natural alexandrite vs synthetic neon blue gemstone opal fire padparadscha paraiba tourmaline phenomenal gemstones pink sapphire vs ruby play-of-color precious metals rare gem phenomena rare gems rare gemstones rare sapphires ruby Russian alexandrite sapphire silver vs gold spinel gemstone star sapphire sterling silver jewelry sustainable jewelry tourmaline engagement ring types of gold vivid gemstone colors zircon gemstone zultanite