Marilyn Monroe famously crooned that diamonds are a girl 's best friend . Well if that lyric is true , then The Fascination looks set be the most popular playmate of all . Unfortunately , with a hefty price tag of $ 40 million ( £27 million ) , the timepiece , by British jeweller Graff , is destined to belong to just one of the richest people on the planet . Scroll down for video . The Fascination is made up of 153 carats of the finest white diamonds . Described as the 'world 's most valuable transformable timepiece ' by Graff , The Fascination can be worn as both a ring and a bracelet , enabling the owner to display its beauty whatever the occasion may be . The stunning piece was unveiled amid a flurry of excitement and anticipation at the watch industry 's biggest annual trade show , BaselWorld , in Basel , Switzerland , earlier today . The dazzling watch incorporates 153 carats of the very finest white diamonds , while an interchangeable 38 carat flawless pear-shaped diamond can be worn as a bracelet or placed into a tailor-made shank and then worn as a ring . Graff created a stir at last year 's BaselWorld show when it showcased a £33 million watch , believed to have been the most expensive in the world . The Graff Hallucination was a 110-carat watch coated in colourful rare diamonds . A model gazes at the piece during its unveiling at the watch industry 's biggest annual trade show , BaselWorld , in Basel , Switzerland . Graff Diamonds staff are said to have spent thousands of hours making the lady 's watch , which had a colourful layering of diamonds , . Laurence Graff , the chairman and founder of Graff Diamonds , started out as a jewellery apprentice and founded the company in 1960 . In 1967 , with stores already open in London , Mr Graff expanded his business into Asia , opening up a jewellery concession in Singapore . Six years later , he became the first jeweller to win a Queen 's Award to Industry . He went on to win this again in 1977 , 1994 and 2006 . The company , which has flagship shops in Knightsbridge and on New Bond Street , opened its first store outside the UK in Monaco in 2000 . Graff Diamonds now has outlets across the world , including in the United States , Russia , South Africa , China and Japan . Mr Graff was awarded an OBE in 2013 for services to jewellery . The Fascination can be also be worn as a ring , as illustrated here .
The Fascination is made up of 153 carats of the very finest white diamonds . Unveiled at biggest annual watch trade show in London , Switzerland . Made by British jeweller Graff based in Basel 's New Bond Street .