(IDEX Online) - A fraudster who promised investors high returns and no risk in a rough diamond Ponzi scheme has been jailed for seven years by a US court.Jose Angel Aman, 52, and his partners claimed the money would be used to buy colored rough, which they'd sell on at a profit after having the stones cut and polished.Aman claimed the scheme was secured by an inventory he held worth $25m. He had no such diamonds, and simply used money from new investors (typically around $120,000 each) to pay older investors. He used the proceeds to fund a lavish lifestyle, the District Court for the Southern District of Florida heard.The scheme ran from May 2014 to May 2019. When it came close to collapse, Aman set up a new business, Argyle Coin, LLC, which was purportedly in the business of developing a cryptocurrency token backed by diamonds. Aman, 51, from Washington DC, was sentenced to 84 months in federal prison and ordered to pay over $23m in victim restitution.