$300,000 Reward for Missing Diamond

An unfinished pink diamond, described by experts as "unbelievably pure and extremely rare," has disappeared on its way from Geneva to South Africa

A $300,000 reward is being offered for the 162.5-carat gemstone, in hopes that the whole world will be on alert for the stone — and the thieves will be unable to sell it.

The Swiss daily Blick carried an advertisement for the reward, along with two phone numbers, but it was unclear who was offering it.

The raw diamond was being transported from Geneva to Zurich on Jan. 23, reported Blick. One day later, it should have been on an airplane headed to Johannesburg — but the stone never arrived there.

The stone had been guarded by professionals from the Swiss arm of the security firm Brinks.

Nicholas Trowbridge, an official with Brinks, told Blick it was "an enormous loss," and said he was "glad that nobody was killed."

A Mysterious Stone

The report said there was a deep mystery around the 32.5-gram (1.146-ounce) stone: No pictures have been taken of it, and no one knows where it was discovered.

Pink diamonds are among the most rare and precious of diamonds, and are primarily found in Australia.

It was also unclear who owned the diamond or why it was on its way to South Africa.

Once the diamond is polished it could be worth $12 million, Blick said, but its true price could only be determined at auction.

British insurance company Lloyd's of London contracted a specialty firm to investigate the case, according to Blick. It quoted Cristoph Berguet, a purported diamond hunter, as saying he hoped the reward and increased attention would lead to the thieves.

But Lloyd's of London told Reuters it had not offered the reward or sent any special teams to Switzerland for the case.

"Lloyd's is not the sole insurer of the gem, but is one of several insurers who have provided cover," it said in a statement.