Volcanic rocks from Israel contain the first known occurrence on Earth of a titanium-rich mineral called tistarite. The discovery suggests that deep-Earth chemistry may differ from what scientists had suspected.

Until now, tistarite had been found only in a single meteorite from Mexico. A team led by William Griffin at Macquarie University in Sydney, Australia, found more of it in rocks from Mount Carmel.

Tistarite forms in chemically reducing conditions, for instance in high-hydrogen environments. The authors suggest that hydrogen or methane might percolate deep into volcanic plumbing systems, creating ultra-reducing pockets in which the unusual mineral can form.

Geology http://dx.doi.org/10.1130/G37910.1 (2016)