Scientists have discovered trace amounts of opal on the surface of Mars via a meteorite that crashed into Egypt a hundred years ago, and it may be the best lead yet for determining whether life once existed on the Martian surface.

Scientists at the University of Glasgow found in a new study that fire opal is typically found near hot springs, a place where microbial life could have thrived in waters teeming with minerals, and could have been preserved within the deposits of opal themselves, much like amber, according to an NBC News report.

The study indicates that future experiments should target suspected opal deposits on the surface of Mars in order to find proof that this microbial life once existed, and that by doing so scientists may learn more about the Red Planet’s history and just how suitable it was for hosting alien life.

The meteorite in question fell into Nakhla, Egypt, back in 1911, and it was believed to have been a piece of rock ejected from the Martian surface at one point and circulated through the solar system before finding its way to Earth. The meteorite was broken into many pieces, 40 of which were recovered, and is currently found at the Natural History Museum. This piece of space rock had trace amounts of opal in it, a gemstone we best know for being in jewelry but is also known by scientists as commonly found near mineral-rich waters, according to a Gloucester Citizen report.

It’s not much opal that was found, but what it does do is confirm that opal is on Mars, which confirms findings from NASA’s imaging and exploration of Mars that indicate that there are indeed opal deposits out there. This is the first time such deposits are confirmed.