NEW YORK, July 31 (Reuters) - The U.S. Securities and Exchange Commission on Monday charged an entrepreneur known as Richard Heart with raising more than $1 billion in three unregistered crypto asset offerings and defrauding investors out of $12.1 million to buy luxuries including a 555-carat black diamond.

In a complaint filed in Brooklyn federal court, the SEC said Heart, also known as Richard Schueler, touted his Hex token, PulseX asset trading platform and PulseChain asset network on YouTube and other websites as pathways to "grandiose wealth."

The SEC said Heart often made superficial "tongue-in-cheek" disclaimers that his offerings were not securities but knew otherwise, as he touted that Hex was capable of 38% returns and "built to be the highest appreciating asset that has ever existed in the history of man."

The SEC accused Heart of spending investor funds on McLaren and Ferrari sports cars, four Rolex watches and "The Enigma," which cost 3.16 million British pounds (then $4.28 million) at auction and was purportedly the world's largest black diamond.

Heart, 43, is a U.S. citizen believed to live in Helsinki, Finland, the SEC said. He did not immediately respond to a request for comment through LinkedIn. Hex, PulseX and PulseChain are also defendants.

The lawsuit seeks civil fines and the recouping of ill-gotten gains.

(Reporting by Jonathan Stempel and Chris Prentice in New York; Additional reporting by Katharine Jackson and Ismail Shakil; Editing by Will Dunham and Mark Porter)