Blue Nile, the largest online retailer of diamonds and luxury jewely, has reported first quarter net sales of $67.9 million, up 34 per cent year-on-year.

The company, founded in 1999, has been one of the dominant figures in online jewelry retail and the latest financial results may well act as a wake-up call to other industry leaders.

Operating income increased by 38.3 per cent to $3.7 million in the quarter, as net income reached $3.2 million. Blue Nile chief executive Mark Vadon has spoken of his delight at the new figures.

"We experienced tremendous growth in our business and generated substantial profitability. Our first quarter performance was driven by significant traction with consumers as a result of the appeal of the Blue Nile customer experience and value proposition," he said.

Diane Irvine, president and chief financial officer, said: "We are pleased with the robust growth in our net sales, gross profit and earnings. While all product categories were strong in the first quarter, we are particularly enthusiastic about the performance of jewelry at price points above $25,000. Our net sales in these price points rose 84 per cent year-over-year in the first quarter, representing our fastest growth product category and reflecting the growing appeal of the Blue Nile brand."

Blue Nile stocks a huge quantity of platinum jewelry, including engagement rings starting at $235. A platinum diamond eternity band, however, will set you back $13,150, demonstrating the impressive range that Blue Nile supplies.

A platinum diamond band for men, with seven round diamonds enveloped in a platinum channel, sells for somewhere in the region of $2,700.

Platinum earrings, meanwhile, range in price from $175 to $525 and necklaces can be bought for anything between $175 and $1,000.