New Delhi, March 15 -- In Delhi's National Museum, on a velvet cushion inside a rotating vitrine, rests a 185-carat diamond.

Unlike the violent past and bizarre superstitions that come with the Koh-i-Noor, the story of the Jacob diamond has closer ties to jeweller Nirav Modi's bankruptcy.

The Jacob diamond-almost double the size of the Koh-i-Noor-is among the 173 jewellery items from the collection of the nizams of Hyderabad that are on display at the National Museum. It is the highlight of the Jewels Of India: The Nizam's Jewellery Collection exhibition (ongoing till 5 May). Seeing it in the vitrine led me to Australian author John Zubrzycki's 2011 book, The Mysterious Mr Jacob: Diamond Merchant, Magician And Spy, which narrates the diam...