(IDEX Online) - Hong Kong's auction houses say gem sales kept booming last year, even though the pandemic forced them to conduct their business online. Christie's, Phillips, Sotheby's and Bonhams all reported record prices in a round-up by the South China Morning Post, although they did not disclose total revenues.The single most expensive item (pictured) sold at a live auction was was a ring with a 12.11-carat fancy intense blue internally flawless diamond, flanked by white diamonds, which sold for $15.8m at the first post-lockdown sale, in July 2020. The high estimate was $12.25m. The price per carat was $1.31m, reflecting what Christie's called "the robust global demand".A close second for price was a 102.39-carat D-color flawless oval diamond, which sold for $15.6m in an unprecedented single-lot live auction, with no reserve, at Sotheby's.