Millerite from the Madan ore field

Millerite is discovered in samples from Krushev Dol and Mogilata deposits in the Madan ore field. It was found in two associations different in appearance and mineral composition. One of them is with light green ferrodolomite, and the other with bright green mariposite (chromium-bearing phengite). Only cobalt and iron are detected as impurity elements in some analyses. They are in small concentrations (below 0.01 apfu). The Ni/S ratio is 0.95. The nickel source is associated with bodies of serpentinized ultramafics cut by ore-bearing veins.