| Breunnerite | |
| Composition: | (Mg, Fe) CO 3 |
Breunnerite is a variety of magnesite, with a magnesium/iron ratio of 90/10 to 70/30.
It has been described by Wilhelm Karl Ritter von Haidinger in samples of Pfitsch pass, Zamsergrund and, two cities of the Ziller Valley, Tyrol, Austria.[1]