Nice specimen of the very rare jouravskite, a mineral only known from two localities wolrdwide, in a matrix of white xonotlite.
The mineral is a Ca-Mn sulphate carbonate.
Jouravskite is one of the rarest members of the ettringite group, found in the Kalahari Manganese fields.
A really showy example of this rarity!
Shipping costs of Registered Mail : Spain 6 $ / Rest of the World 10 $