One of China’s rarest stamps sold for HK$6.9 million ($890,000) at auction in Hong Kong, the auctioneers said Wednesday.

With just 32 recorded copies, the Qing Dynasty “1897 Red Revenue Small One Dollar” stamp is “China’s rarest regularly-issued stamp”, Interasia Auctions said in a press release.

The bright red stamp, symbolising luck and good fortune in Chinese culture, is rare because the characters “Qing Dynasty postal service, one dollar” were considered too small, prompting the printing of a second version.

The stamp was part of a three-day auction of Chinese, Hong Kong and Asian stamps which ended Monday bringing in a total of HK$71.9 million, Interasia said.

“Philately has a special place in Chinese culture, with rare stamps regarded as important cultural icons and treasures, just like art,” auction house director Jeffrey Schneider said in the statement.

A pair of rare stamps bearing an accidentally inverted picture of Chinese nationalist leader Sun Yat-sen sold for more than $700,000 in Hong Kong last October.

Mainland Chinese are regular buyers of the top lots at sales of art, jewellery and wine as Hong Kong positions itself as an auction hub for Asia as well as the gateway to China’s vast market.