NOPE! Photo via AP Images.

Take care when picking up pretty little baubles spotted while taking a stroll: One German woman recently came upon what she thought was a chunk of amber, only to discover—after she’d put it in her pocket—that it was in fact a piece of flammable phosphorus left over from the Second World War.

That’s according to the Telegraph:

The 41-year-old was walking on Elbe’s riverbank in Wedel, near Hamburg, when she pocketed what appeared to be the precious stone. Upon drying, it quickly ignited in her jacket. Passers-by and firefighters to intervene.

According to the local authorities, the phosphorus came from a WW2 incendiary device. Passersby intervened and called firefighters, who quickly extinguished the blaze.

It’s still common to come across unexploded ordnance from World War II. Smithsonian magazine reported in 2016 that there’s still an incredible number of unexploded bombs left in Germany alone. (Any number would be incredible, really.):

Even now, 70 years later, more than 2,000 tons of unexploded munitions are uncovered on German soil every year. Before any construction project begins in Germany, from the extension of a home to track-laying by the national railroad authority, the ground must be certified as cleared of unexploded ordnance. Still, last May, some 20,000 people were cleared from an area of Cologne while authorities removed a one-ton bomb that had been discovered during construction work. In November 2013, another 20,000 people in Dortmund were evacuated while experts defused a 4,000-pound “Blockbuster” bomb that could destroy most of a city block.

“Although the country has been at peace for three generations, German bomb-disposal squads are among the busiest in the world,” added writer Adam Higginbotham.

Not everything you find on a beach is gonna be ambergris, unfortunately.