The jury was still out on diamonds, but the verdict on Don Regan was clear yesterday: Nobody was calling him a girl's best friend.

In a remark reminiscent of his controversial comment last fall that women are "not going to understand throw weights," the White House chief of staff Wednesday asked a small group of reporters: "Are the women of America prepared to give up all their diamonds?" in favor of sanctions against South Africa.

The answer around town ranged from outrage to guffaws that could be heard from here to Pretoria.

"I find it offensive," said Rep. Patricia Schroeder (D-Colo). "What's so amazing is that just a couple of weeks after this great Liberty celebration, with a woman holding up the lantern for liberty and freedom, this guy thinks she'd trade it for a diamond."

"And what would men give up? Their Mercedes?" asked socialite Jayne Ikard. "I'm going to sit on the fence until I hear what the men will give up."

"Who do they have making policy down there? Marie Antoinette?" asked Christopher J. Matthews, spokesman for House Speaker Thomas P. O'Neill, referring to Regan as "Diamond Don."

Regan apparently made the remark twice Wednesday, the first time in a background briefing to reporters, including one from the Baltimore Sun, who reported the comment. UPI reported later that Regan repeated it at a state dinner that night.

By 3 p.m. yesterday, from the Hill to K Street, Washington was clucking.

"I'll give up my jewelry if he gives up his throw weights!" said journalist Nancy Dickerson.

"No way," Joan Haney, manager of Bailey Banks & Biddle Jewelers at Montgomery Mall, said in response to Regan's question. "And not in my neighborhood; I live in Potomac."

"I'm wondering if Don Regan is going to give up his three-martini lunch," joked Jim Rosenheim, owner of the Tiny Jewel Box. "It must be some sort of scare tactic."

With nearly $1.6 billion spent on diamond engagement rings in 1984, this is serious business. Not to worry: The message from Melart Jewelers was that women can relax.

"I don't think the American populus -- male or female by the way -- has to give up their jewelry," said Martin Stein, an executive vice president with Melart. "I think it's not a valid question," he said. "Fact of the matter is only a small percentage originates from South Africa. Diamonds come from all over the world."

"I have a feeling diamonds are not as popular as they were 40 years ago anyway," said public relations executive Joan Braden. "None of my kids wanted diamonds for engagement rings. They all wanted gold bands. Only the very rich want diamonds and they'll find someplace else to buy them and pay the extra."

Some people, of course, have a major investment in women who lose interest in gold and diamonds. The real kind, that is. Madame Wellington, who has made a career out of peddling faux stones, said some women already are giving up their diamonds.

"We feel the increase now," she said. "People are very upset about the South African thing. Women gave up wearing real diamonds a long time ago because of the expense. Now, we have women writing in on mail orders that they stopped buying the real thing because of South Africa."

Helga Orfila, whose shop Helga O specializes in costume jewelry and accessories, agreed: "People have turned to costume jewelry because insurance alone costs a fortune. I don't even wear my real jewelry anymore. I wish I could sell it."

But that all was beside the point to those who took the remark as an affront.

"I believe American women are informed about the full range of public policy issues, including human rights in South Africa, and I don't believe they put material things above those concerns," said Rep. William Gray (D-Pa.).

"I don't think that's the position of American women," said the Rev. Jesse Jackson. "I think that American women will chose their character over their carats."