Genre: Promotion

Courtesy of the Victoria and Albert Museum , London You might want to stash the rhinestones . The jewels on this list are going to give the rocks that you 've got some serious inferiority complexes . Grab a loupe and step inside . But do n't even think about pocketing anything ... you will be searched at the end of the tour . And before you start assembling your rappelling gear in preparation for a midnight heist , know that the malediction placed on these beauties makes the Hope Diamond look like a lucky charm . Keep those grubby paws to yourself ! Wela49 Aquamarines , which range from cerulean to greenish-blue , tend to have greater clarity than the related emeralds . Its name is Latin for " sea water . " Greek and Roman sailors believed that the limpid stones would bring them luck . Dom Pedro , the largest cut aquamarine , is 2 feet tall and weighs over 10,000 carats . It is displayed at the Smithsonian . Lee Boltin Topaz crystals can grow to massive proportions . The nearly 23 , 000-carat American Golden topaz , also at the Smithsonian , is among the world's largest faceted gems . At the size of a small watermelon , it 's almost comically huge . Even Joan Collins could n't pull off that monster . Photograph by sulla55 . Houston Museum of Natural Science , 28.2006 Opals are formed over many centuries by the deposition of silica dissolved in water . Their mysterious , almost holographic refraction of light is thought to be caused by differences in the size of the spheres of silica that form them . Opal can replace other substances , even wood and bone , which leads to the formation of opal fossils . Los Angeles County Museum of Art , Nasli and Alice Heeramaneck Collection , Museum Associates Purchase ( M. 71 . 1 . 35a-b ) , www.lacma.org As if seeing all of these gorgeous baubles arrayed temptingly before you were n't enough of a knife to the heart , here 's an actual knife . With a jeweled handle , of course . It is made of nephrite , one of the two gemstones referred to as jade . The other is jadeite , which is more valuable .