Emeralds and diamonds glistened against sable coats, shimmery sequined gowns rustled and expensive perfumes competed for recognition last night at the National Symphony Ball -- one of Washington's more fashionable annual social occasions.

Founded in 1954 by the late Marjorie Merriweather Post, the Symphony Ball is one of the few here which has maintained status. More than 1,000 people gladly paid $200 each to help the National Symphony Orchestra and be seen waltzing around the Sheraton Washington Hotel in white tie and taffeta.

"In a town that has the Bullets, the Caps, and the Redskins, the National Symphony is the only winner in town," said Gerry McKiernan, congressional liaison of the Commerce Department. "That's why we came."

This year's honorary chairman was Betsy Bloomingdale, wife of Diner's Club founder Alfred and a best friend of the first lady. Bloomingdale, however, canceled at the last minute plans to attend because her husband was ill.

Nonetheless, that didn't stop most of The Group from flying East for the ball. It was a regular old bicoastal reunion, very reminiscent of inaugural week. There were Jack and Bonita Wrather, Armand and Harriet Deutsch, Justin and Jane Dart, Earl and Marion Jorgenson, Jean and William French Smith, Walter and Leonore Annenberg, and Bob and Audrey Meadows Six.

"I flew in from London, and it's fun to be all together here," said Bonita Granville Wrather. "Tomorrow all of the Californians are going over to the White House to see a movie in the afternoon. We'll be seeing 'Reds,' and I hear Warren Beatty and Diane Keaton will be there."

"I hope we do get to see the Reagans , but we'll see," said Audrey Meadows Six. "I never dare call them. I wouldn't dream of it. They're both so busy."

Attorney General William French Smith made one other party stop before the ball. He took a birthday cake to the office of Sen. Strom Thurmond (R-S.C.), whose 79th birthday is today. "My cake only had four candles on it, but the one his kids brought had 79. It looked like a forest fire. That guy is absolutely amazing. He actually blew them all out."

This year's ball was sponsored by Moroccan Ambassador and Mrs. Ali Bengelloun and a Mideast touch permeated. A team of artisans sent by the king of Morocco began decorating at midnight Thursday. Huge photographic murals of the ancient Moroccan city of Mekenes adorned the walls, pink and silver Moroccan fabric garnished the tables, and gazebo-like tents hung over the doorways.

Even the menu was spiced with Moroccan cuisine with Harira soup, roulade of veal, and Moroccan pastries. The Gene Donati Orchestra played "I Could Have Danced All Night." And they did.