Charlie Naysmith found the ambergris, the technical term for the substance vomited or excreted by sperm whales, while walking along Hengistbury Head, near Bournemouth.
The Daily Mail reports that the lump is potentially worth £40,000 - a pound of ambergris sells for as much as £6,300 ($10,000).
Charlie's father Alex said that they have contacted the authorities to find out more background on the unusual find: 'He is into nature and is really interested in it.
"We have discovered it is quite rare and are waiting for some more information from marine biology experts."
The substance is sought-after by perfume-makers as it has traditionally been added to fragrances to prolong the scent.
During the time of the Black Plague, it was believed that carrying a ball of ambergris would prevent the spread of the disease, due to the fragrance covering the smell of the air.
Charlie has reportedly said that he is thinking of putting his new-found riches into an animal shelter.