As it prepares to formally open a new store at the Atrium Mall in Newton Nov. 15, tiffany & co. wants everyone to know its famous jewelry is as much for hoi polloi as for the carriage trade. "Tiffany has been a well-kept secret," asserts Michael J. Kowalski, the company's president and chief operating officer. "We've been trying to aggressively communicate the message that Tiffany is more affordable than you think." On first hearing, that seems a bit of a stretch. For example, tiffanys 1997 holiday catalog features diamond crab-shaped earrings for $ 6,900 - a gewgaw perhaps for the late Audrey Hepburn, star of "Breakfast at Tiffanys," but hardly a trinket that often turns up in the jewel box of a soccer mom. Aside from fine diamonds, the Tiffany catalog also includes $ 17 crystal beer mugs, and an assortment of cigar tools, and golf gear, such as a $ 50 silver golf tee. A luxury retailer can lose the cachet of exclusivity when it widens its customer base. So far, though, Tiffany - with its signature powder blue box - has kept its tony image even as it dabbles in TV advertising. Management has "exhibited excellent execution" of its goal to "concurrently attract new customers, particularly young shoppers, without disturbing its carriage trade clientele," Rodman & Renshaw analyst Harry A. Ikenson wrote in August. As Tiffany broadens its market and opens new stores, annual sales have grown 12 to 15 percent for much of the decade. In 1993, the company reported profits of $ 15.7 million on sales of $ 486.4 million. For its latest fiscal year, Tiffany had profits of $ 58.4 million on sales of $ 922.1 million. About 57 percent of last year's sales came from the United States, about 27 percent from Japan. By the end of the year, Tiffany said it will operate 27 stores in the United States and 92 additional retail locations overseas. Sales at older US stores, a measure of performance that Wall Street watches closely, were up 11 percent, 12 percent, and 12 percent for the past three years, respectively, and up 8 percent for the first half of this year, Tiffany said. The store at the Atrium Mall will be Tiffanys second in Greater Boston and one of four US stores it will open in 1997. Tiffany also operates a store at Copley Place. Because there are many cities not currently served by a Tiffany store, the company believes that as a well-known player in the $ 25 billion US fine jewelry market, it has substantial room for growth by opening stores in new markets. It's conventional wisdom that luxury retailers thrive when the stock market booms, but Kowalski says there are factors other than a bull market behind Tiffanys success. "One of our best holiday seasons was in 1987 just after the market crashed," he said. A big reason for the company's growth, Kowalski said, is consumers' love affair with quality brand names over the last few years. "The general move toward value is very much to Tiffanys benefit." Shares of Tiffany stock, which traded above 48 in June on the New York Stock Exchange, have since settled to about 40 on fears that New York-based Tiffany does too much of its business in some volatile Asian markets. Shares yesterday were up 7/16 to close at 41 1/16. On Monday, Ikenson reiterated his buy rating on Tiffany. "In our opinion, the recent share-price weakness reflects investor concern over tiffany & co exposure to Hong Kong," the analyst wrote. "However, Hong Kong represents only 2 percent of Tiffanys business. Therefore, we believe this represents a buying opportunity." Ikenson said he anticipates a "solid third quarter" when Tiffany reports its earnings later this month.