Ambergris is used in perfume making and is a rare material, hence the large estimate, which, given how highly sought after it is, could even be a moderate one at that.

Ambergris, from the whale intestine, is used in the perfume making process as it is believed it makes the scent of the perfume long lasting and enhances the smell.

The piece weighs around 1kg, Adam Partridge explains: ''Ambergris is formed in a sperm whale's digestive system and is passed either as vomit, or as part of the faeces."

See the ambergris and Adam Partridge's catalogue on Barnebys here.