(IDEX Online) - Elvis Presley's custom-made gold ring, featuring a 7.56ct VS2 diamond, could fetch as much as $1m when it is auctioned later this month.It is among the headline lots at a sale of showbiz memorabilia in Los Angeles, USA.The ring was designed by the King with the TCB logo - Taking Care of Business - the name he gave to his band, together with a pair of lightning bolts.The ring (as pictured) contains a large cubic zirconia but is being sold with the original diamond, graded at P-Q color with a faint blue fluorescence, along with its 1981 GIA certificate.Presley gave the ring to JD Sumner, a singer in his band, on stage during a 1975 performance in Asheville, North Carolina, telling the crowd it had cost him over $40,000.The round brilliant-cut diamond is surrounded by a halo of another 2.25 carats of diamonds and the ring weighs 34.2 grams."It's the quintessential Elvis jewelry piece," said Brigitte Kruse, founder of GWS Auctions, which is also offering the 1975 FLH 1200 Harley-Davidson that he rode around the Graceland estate in Memphis.She said the ring could fetch anything between $500,000 and $1m at the 300-item auction.A duplicate of the TCB ring was buried with Elvis, according to accompanying documentation.