The Harry Winston Diamond Company saw its shares jump 5.7% to $13.91 as trading opened for the week on Monday, and nearly double its average trading volume.

Harry Winston, which owns 40% of the Diavik diamond mine in Canada, supplies rough diamonds to the global wholesale market and sells top-quality cut and polished diamonds at its luxury stores.

Approximately 25% of Harry Winston's diamonds are sold to Tiffany & Co, which also saw its shares rise this week, albeit by a more modest 1.3%.

In February, the diamond company announced that it would be establishing a Chinese subsidiary and planned to open nine diamond jewelry boutiques in China in 2011.