The political upheaval convulsing the Middle East is pushing up the price of high-quality gems, traders say, as the region's well-heeled look to convert their wealth into easily portable property.

The Middle East and North Africa have been rocked by unrest since an uprising in Tunisia in January brought down the government there and led to similar protests in Egypt which ousted president Hosni Mubarak last month.

Martin Rapaport, chairman of the Rapaport Group which runs one of the world's largest diamond trading networks, said prices for high-quality stones were being driven up as wealthy people in the region look to acquire "flight capital" -- high value items they can carry easily if they need to flee their country.

Gold and silver reached historic highs last week, with investors seeking refuge in safe havens as fears about the unrest spreading to the oil-rich Gulf states sent crude prices soaring above $100 a barrel.

Unlike bullion and cash, diamonds offer an easy way to transport huge sums without attracting too much attention, Rapaport said.

"If you want to move five million dollars out of the country and you wear a diamond ring and your wife or girlfriend wears a diamond ring, nobody tries to stop you at customs," he told AFP.

"It's like an insurance policy, plus it appreciates."

Rapaport said that while growing demand from China and India was fuelling price rises for low to medium grade gems, Middle East concerns were pushing up prices for higher quality diamonds.

The asking price for internally flawless D-colour three-carat diamonds on the RapNet diamond trading network rose to $73,000 per carat in late February, compared with $54,199 per carat a year earlier -- a jump of nearly 35 percent.

Rapaport Group research found average prices for all polished diamonds in February had risen 4.7 percent since the start of the year.

Continuing uncertainty in the Middle East could push prices even higher, Rapaport said, and he warned that if control of Saudi Arabia's oil supplies came into question the price of large diamonds could rise by as much as 50 percent in a short space of time.

Chang Hatta, the chairman of Hatta New World, a high-end jewellery firm based in Hong Kong and Taipei, said that for those who could afford them, the very best gems were a safe bet in tumultuous times.

"All the royal families in the Middle East buy precious stones. They have a problem in the Middle East. You can't carry the building, you can't carry the money. This you can carry," he told AFP at the Hong Kong International Jewellery Show this week.

At Hatta's glittering stall in the show's "Hall of Extraordinary", it was clear his products are aimed at those for whom money is no object -- and ostentation is not a dirty word.

Window after window glistened with cartoonishly large emeralds, ruby rings like knuckledusters, sapphires and gold, gold, gold.

The piece de resistance sat in a display by the stall's entrance -- a diamond-studded necklace of staggering opulence carrying a stunning, vivid turquoise pendant of Brazilian paraiba, one of the world's rarest gems.

Nikhil Jain of Bangkok-based Allure Jewels, which has been selling jewellery to royal families for three generations, agreed the unrest in the Arab world was affecting prices.

"In the Middle East, people are moving out of these countries. They don't want to live with the political hassle," he said.

Those rich enough to stock up on gemstones may not need to -- as Hatta observed.

"You can put a billion dollars' worth of stones (in your pocket), can carry, can walk away. So all the royal families do this. You know what I mean?" he said.