Until recently, the largest opal ever found was 6,100 carats. That's paltry compared to the opal discovered by noted designer Stuart Hughes and his associates in Australia. They uncovered the largest opal to ever be found - a whopping 55,000 carats!.
The estimated value is at least $1 million, uncut. Once Hughes cuts the stone up and turns it into magnificent jewelry, the total value will increase quite a bit.