A rock on Mars spilled a surprising yellow treasure after Curiosity accidentally cracked through its unremarkable exterior.

When the rover rolled its 899-kilogram (1,982-pound) body over the fragile lump of mineral in May of last year, the deposit broke open, revealing yellow crystals of elemental sulfur, known as brimstone.

Although sulfates are fairly common on Mars, this represented the first sulfur in its pure elemental form found on the red planet.

What's even more exciting is that the Gediz Vallis Channel, where Curiosity found the rock, is littered with objects that look suspiciously similar to the sulfur rock before it got fortuitously crushed – suggesting that, somehow, elemental sulfur may be abundant there in some places.