For a while, in the Middle Ages, there was a real craze for trying to turn unassuming lead into pure, gleaming gold.

Perhaps those ancient alchemists should have been building a particle collider. According to a new paper, CERN’s Large Hadron Collider produced about 86 billion gold nuclei from high-speed lead nuclei during the facility’s second run, between 2015 and 2018.

This is not actually much gold – mere trillionths of a gram. Nor does it last very long – just fractions of a second. But what’s really cool here is the way physicists quantified the gold production: by counting the number of protons accompanying neutrons involved in the lead interactions using the ALICE (A Large Ion Collider Experiment) detector’s zero degree calorimeters (ZDCs).