A sapphire and diamond necklace that has an estimated sale price of some $1.5 million was acquired at the elite Van Cleef & Arpels. Worn to the Met Gala, the shimmering piece would have surely turn heads. But Nazi origins creating the fortune that made the original purchase of this shimmering necklace possible may repel to some. This is one of 700 jewels being put up for auction by Christie’s beginning online May 3 and in person May 10. Expected to gross $150 million — aided by items such as a jadeite and diamond necklace with a high-water price of...