Some October jewelry auctions are bound to receive a lot of media attention — they features jewels from the estates of Princess Diana and the "Diamonds are a Girls Best Friend" crooner, Marilyn Monroe.

Among the Monroe collection, offered by Christies: A platinum "eternity band," with 35 baguette-cut diamonds (one of the stones is missing), she received after her 1954 wedding to Joe DiMaggio. It’s valued from $20 to $50,000.

Also, Manhattan auction house Guernseys is auctioning off a necklace with 164 marquise-cut diamonds and five large South Sea pearls that was worn by Diana, Princess of Wales, in her last public appearance, three weeks before her fatal crash. The bidding for that starts at $500,000.