Mr Jim Quinn, president of immortal New York-based jeweller Tiffany & Co, tells a story about how his Irish grandfather accidentally arrived in the US earlier this century.

The young man was, so the tale goes, escorting a friend and emigrant to a port somewhere in the south of Ireland when, on a whim, he decided to put himself on the boat too. Unprepared and penniless, it suddenly struck him that he wanted to get a piece of the great, mythical American dream.

Eight or so decades later, the boy on the boat is transformed into his grandson - a polished, educated and successful American who heads up one of the most classic retail establishments the US has ever spawned.

Looking back at a grand total of four Irish grandparents, Mr Quinn is aware of the serendipity of it all and, despite his position at the helm of what might be seen as a waspy institution, is unafraid of broadcasting his Irishness.

He says Tiffany is a more diverse place than it may have been in the past, with workers and customers drawn from varying levels of society rather than being concentrated at the top. He says you can spend anything from $100 (€86) or $1 million on a Tiffany product, depending on your mood or budget.

Despite holding "every kind of jewellery product at every price point", however, the company's flagship product remains the solitaire diamond engagement ring with a classic six-pronged Tiffany setting. Mr Quinn says "tens of thousands" of such rings are sold around the world every year, with $10,000 the most appealing price for the just-engaged market.

And of course, the just-engaged become the just-marrieds with a wedding list and then the new parents in need of a Tiffany rattle for their baby.

Mr Quinn's background is punctuated with exactly the social progression that Tiffany signifies for many of its clients. The impulse emigrant grandfather bettered himself by becoming the caretaker of a local Catholic school, while the patriarch on the other side was a publican. Mr Quinn's father was the first of the wider family to attend college and promptly showed his appreciation by becoming a professor. The next generation is one of lawyers, bankers and presidents of Tiffany.

Coming from a family where education has held such importance, Mr Quinn likes to give something back to the business of learning. He is a prominent donor to Hofstra University, where an athletic scholarship helped him to earn his BA degree in communications. Most recently, he has coupled his appreciation of education with his Irish heritage by becoming chairman of the North American Board of UCD's Smurfit School of Business.

Having earned his MBA from Pace University by night while working at Citigroup, Mr Quinn appreciates the pain and benefits attached to the degrees.

He joined the Smurfit School's board for the same reason that he began to work at Tiffany almost 20 years ago - a friend recommended him for the position. In the case of Tiffany, he began his career selling the company's products as corporate gifts. At the time, the firm was privately held and had eight stores in the US. Now, 70 per cent of Tiffany, the public company, is held by institutions and it has more than 130 outlets around the world.

Even enduring success stories such as Tiffany have not had the easiest of rides over the past couple of years, however, with the fallout of September 11th hitting the luxury retail market more than most. Sales declined that year but moved into growth mode again in 2002 and have continued to increase.

Mr Quinn is confident that the second half of this year (including the all-important Christmas period) will be particularly successful for the firm, which has already reported sales of $442 million for the second quarter, up 18 per cent on 2002.

He points out that people continue to celebrate special occasions even when the economy looks gloomy - Tiffany engagement rings continue to sell regardless of the size of the US deficit.

This optimism seems to be borne out by statistics, with figures from the US Commerce Department showing that consumer spending has risen slightly in each of the past two months.

This spells good news for Tiffany's market position - which Mr Quinn, as the man at the top, can claim no small credit.