A man in San Francisco trades diamonds for horses.

An organization in Las Vegas exchanges diamonds for antiques cars.

And some people in Southern California are offering diamonds for real estate.

"I have four diamond sales in escrow right now," said Sandra Lane of Allstate Realty in Carlsbad.

"Many realtors are accepting commissionss in diamonds," Harvey B. Levitt, president of the International Gemological Society in Newport Beach, added.

Bartering in diamonds is big business, according to Levitt, "and it is going to become very big business."

"We take the lab report and put it through a computer," he said, "and then we give the figure to both the buyer and seller, and we give it in eight currencies. We act as a third party with no partiality, unlike some houses that give appraisals on stones that they sell." Most of his group's appraisals are done for insurance purposes.

Lane uses Levitt because, she said, "We know real estate, but we don't know diamonds."

And, Levitt added, because of their fiduciary relationship; real estate brokers have to be careful about what is being offered in lieu of money.

Trading in diamonds can be tricky. For instance, there are what Levitt calls "magic numbers."

"A one carat diamond is easier to sell than an offsize," he said.

Keeping the diamonds intact during or even after a transaction may be difficult. "I read about a man who traded $800,000 of real estate for diamonds that he took home, where he was robbed," Lane said.

Levitt's organization will certify that a diamond is the same as one on a lab report and then will seal the diamond and send it to the escrow holder to eliminate switching.

"There has been cases where imitations have been substituted," Levitt said, "but 99 percent of the time, the switching is in error. It is not fraud."

That stems from the fact that many diamonds may be used in a transaction.

"Generally," Levitt said, "multiple diamonds are traded for one piece of real estate. That's better for liquidity. How many people are interested in a $100,000 diamond? It's a narrower market."