Kernite

Kernite is a fairly common ore type that yields a large amount of mexallon. Besides mexallon the kernite also has a bit of tritanium and isogen. Available in 0.6 to 0.1 security status solar systems.

Kernite is a reliable mid-tier Mexallon source. It sits in the band where the ore is worth hauling but the space is not yet dangerous enough to need an escort.