Book excerpt: It was a scandal that rocked the highest echelons of the British Raj. In 1891, a notorious jeweller and curio dealer from Simla offered to sell the world's largest brilliant-cut diamond to the fabulously wealthy Nizam of Hyderabad. If the audacious deal succeeded it would set the merchant up for life. But the transaction went horribly wrong. The Nizam accused him of fraud, triggering a sensational trial in the Calcutta High Court that made headlines around the world...