[Photo provided to China Daily]

Old photos on show reveal the traditional way by which oysters were harvested in the Persian Gulf, which once produced some of the world's finest natural pearls.

To collect the pearls, divers held one rope that connected them with the pullers and another one attached to stones to accelerate descent.

They normally searched the waters for two minutes at a time.

As pearls are formed by accident, the divers needed to open hundreds of shells to find a quality pearl.

Bari says natural pearls have been collected in the Persian Gulf's waters for more than 7,000 years.

"During this time, exporting loose pearls was a major source of income for countries such as Qatar, and they became a significant part of the region's rich heritage and identity."

The region's pearls trade helped to link Eastern and Western cultures in the long course of history.