Silvite or o silvine (KCl, potasium chloride) from Súria. Silvite, like halite, crystallizes in cubic system and has a hardness of 2. Crystals of silvite are colorless if pure, however often they’re reddish in Bages because the content of iron oxides. Silvite is easily identified by its spicy taste, more or less bitter according to its amount of carnalite (hydrous magnesium and potassium chloride) traces.
Silvite is exploited in mines of potash nowadays in Súria, Balsareny and Sallent and, until 1990, in Cardona as well where the mine achieved -1000 m depth. In plain, unfolded areas, silvite is found in two layers, 100 m below the top of the Cardona formation. Usually, centimetric sheets of silvite and halite are blended. Then the rock is called silvinite. The word potash means any potassium containing sedimentary rock. Silvite is used mainly in fertilizers.
In the photography, the appearance of a just mined mineral: a mass of tiny, orange crystals of silvine that is crossed by a layer of colorless halite crystals.
[photo Jordi Badia]