FERROMERRILLITE IS THE FIRST FIND IN METALLURGICAL SLAGS
In the fayalite slags of the Shuvakish iron-smelting plant, we discovered a rare mineral - ferromerrillite. The studied slags are a product of bloomery iron production. The mineral is found in the matrix of glass, where it is confined to phosphorus-containing fayalite. The chemical composition of the mineral is well recalculated to the formula Ca9NaFe2+(PO4)7, i.e. it is the iron analogue of merrillite and belongs to the whitlockite group. An assumption was made about the existence of several more new minerals in the whitlockite group - Sr-ferromerrillite (Sr9NaFe2+(PO4)7), K-ferromerrillite (Ca9KFe2+(PO4)7) and manganomerrillite (Ca9NaMn2+(PO4)7).