The British Museum said 60 items have already been returned, with a further 300 identified and due to be returned imminently.
Classic Greek and Roman gems that “may be cast from a mould or engraved by hand” are among the missing items.
“They may feature images of famous individuals from the Classical past, of mythological scenes, animals or objects,” it added.
The gems are said to be of differing quality and some will be fragmented or damaged. A Roman sard Intaglio, a Roman cameo in orange glass and an Intaglio in blue glass are pictured on the site.
Golden rings, ear-rings and other pieces of jewellery from the Late Bronze Age and the Hellenisitic and Roman periods are also missing, it said.
Museum chairman and former chancellor, George Osborne, previously said an estimated 2,000 artefacts had been taken.
But the full scale of the loss may never be known due to gaps in the museum’s inventory.
The website also outlines the steps The British Museum is taking to recover the items such as registering them with the Art Loss Register.
It states: “We have established an international panel of specialists, including leading figures in the study of gems and jewellery, who will offer their expertise to assist us in identifying and retrieving the lost items.
“We are actively monitoring the art market.”
The museum is also working with the Metropolitan Police and has established a recovery “hotline” as part of efforts to find the artefacts.
In August Chinese state media called for the return of its artefacts from the museum “free of charge” in the wake of the scandal.
The Chinese government has not made any public statements on the issue.
The British Museum has about 23,000 Chinese objects – including items from the Tang, Shang and Zhou dynasties – making it the biggest collection of Chinese antiquities in the West.
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