The market for eye-catching but affordable costume jewellery has grown significantly since the early days of Argento.
But Argento founder Pete Boyle, who started out in business as a teenager selling mirrors at the Ballyshannon Folk Festival, said he was not in the business of creating trends in jewellery.
He said: "We may make many claims but we can't claim to set trends.
"We follow the trends that are coming and spend a lot of time looking for new products.
"But we are not big enough to start new trends, though we do try to follow them.
"Our job is to try and find new things – and get them first before our competitors do."
Argento sells jewellery brands like Pilgrim and Thomas Sabo and has also started making its own jewellery in Northern Ireland under the in-house brands of Dirty Ruby and Karma.
It has also stocked Pandora –but Mr Boyle said new openings such as Newry and Portadown would not include the popular Danish brand best known for charm bracelets, as Argento is also a franchise holder for Pandora and runs separate shops.
He said Argento had started producing its own jewellery under the Dirty Ruby and Karma brands.
Mr Boyle said the company also hopes to eventually sell Karma products wholesale – and has also established a charity initiative on the Karma range.
One-tenth of sale proceeds from the Karma range are donated to a charity chosen by every store.
"We have always seen it as important to give to charity but we haven't always shouted about it," Mr Boyle said.
The company has also sponsored the young Irish surfer Gearoid McDaid.