 He countenanced the risky operations of the banker John Law, whose bankruptcy led to the Mississippi bubble, a disastrous crisis for the public and private affairs of France.It was an early example of the bursting of an economic bubble.On 6 June 1717, under the influence of Law and the duc de Saint-Simon, the Regent persuaded the Regency Council to purchase from Thomas Pitt for £135,000 the world's largest known diamond, a 141 carat (28.2 g) cushion brilliant, for the crown jewels of France.