Two pistols made from a 4.5 billion-year-old meteorite could fetch $1.5 million when they are auctioned later this month.

Constructed from part of the Muonionalusta Meteorite, which was discovered in Sweden in 1906, the working .45 caliber pistols offer an unusual take on the classic 1911 handgun design. Experts believe that the meteorite slammed into Earth about 1 million years ago, although the meteorite itself is thought to date back some 4.5 billion years.

Dallas-based auction house Heritage Auctions will be selling the pistols, either individually or as a set, at an auction on July 20.