Coastal protection authorities in Sardinia confiscated the plastic bottle of fine sand from the man's luggage at Elmas airport.
He was identified only as a French tourist and was fined 1,000 euros.
Since 2017, the white grains of sand from Sardinia's beaches are considered a protected resource.
The trade of sand, pebbles and shells was made illegal, and punishable with fines of up to 3,000 euros.
It seems harmless enough at the time, after all, what difference can one rock or jar of sand make you may ask?
Erosion
Conservationists say collecting sand or pebbles adds to the problem of erosion in particularly sensitive coastal areas that are already under siege from sea swells.
"These behaviours not only harm the environment but also compromise the maintenance of the coastline for the sustainable development of tourism in Sardinia," the island's authorities said in a press release, quoted by local media.
For several years, Sardinia has prohibited visitors from taking sand from its beaches and sanctions offenders with heavy fines.
In 2015, local citizens set up a Facebook page entitled "Sardinia robbed and plundered" to share accounts of sand being stolen, two years before a new law came into force.
Similar rules around the world
In August 2019, a French couple were arrested in Sardinia with 40 kilogrammes of sand in their car as they were about to board a ferry bound for Toulon.
England also has strict rules about collecting pebbles from beaches, punishable with a fine of up to 2,220 euros.
In the US state of Hawaii since 2013, taking even small amounts of sand from beaches there now can lead to fines of up to 100,000 dollars.
Here in France, the pebbles at Ertetat beach in Normandy are so popular with tourists that signs have been put up to warn people that they're not allowed to collect them.
