See the $68m necklace on display in Singapore

This sparkling necklace can indeed be called "diamond in the rough".

Known as L'Incomparable, this glittering necklace features an egg-sized diamond. It was discovered by chance in a pile of mining rubble about 30 years ago, by a young girl in the Democratic Republic of Congo. She gave it to one of her relatives, who then sold it to diamond dealers, Mail Online reported.

It features a yellow, internally flawless diamond of more than 407 carats suspended from a rose gold setting that is studded with 90 white diamonds weighing nearly 230 carats.

Diamond collectors, though, will have to dig deep to buy it - it costs US$55 million (S$68 million).

The necklace, created by luxury jeweller Mouawad, will be the flashiest item on offer at the Singapore JewelFest from Oct 11 to 20.

"Serious interest" has been expressed by a couple of potential buyers from Asia, Mr Jean Nasr, managing director of Mouawad in Singapore told Reuters. He refused to identify the possible customers.

He said: "People who will get something like this are looking at it from a different perspective, because this is definitely an investment piece."

L'Incomparable was completed last year and is certified as the priciest necklace in existence by Guinness World Records earlier this year.

Mr Filippo Melchionni, who is in charge of guarding L'Incomparable and the rest of the jewellery on show, is taking no chances.

Security includes armed guards, plainclothes supervisors, cameras, motion detectors and bullet- proof display cases, but the most critical time is when the pieces are shown to customers.

"This is the moment that the stones are at risk because they can be passed hand-by-hand. They can be exchanged," said Mr Melchionni, chief operating officer for Asia-Pacific at the Ferrari Group, an Italian logistics company for luxury goods.

"Every night, it is going back to our vault. We have an armoured truck to move the stones."

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