Ludwigite

Ludwigite is a magnesium-iron borate mineral: Mg₂FeBO₅.
Ludwigite typically occurs in magnesian iron skarn and other high temperature contact metamorphic deposits. It occurs in association with magnetite, forsterite, clinohumite and the borates vonsenite and szaibelyite. It forms a solid solution series with the iron-iron borate mineral vonsenite.
It was first described in 1874 for an occurrence in Ocna de Fier, Banat Mountains, Caraș-Severin County, Romania and named for Ernst [Ludwig |Ernst Ludwig], an Austrian chemist at the University of Vienna.
File:Forsterite-Ludwigite-34581.jpg|thumb|left|Ludwigite needles and sprays as inclusions in a peridot crystal from Sapat Gali, Kohistan [District, Pakistan|Kohistan District], Pakistan. Size 2.8 x 2 x 1.1 cm.