The Nyköpingsgruvan pegmatites are located on the northern part of Utoe
Island, Sweden, and consist of two pegmatite bodies that transect the
Nykoepingsgruvan iron formation. During crystallization, tourmaline
composition evolves from Al-rich schorl through elbaite and phases
intermediate between elbaite and rossmanite to Ca-bearing
elbaite-rossmanite and finally to Ca-bearing elbaite.
X-site composition of rossmanite from Utö, Sweden, as reported by Selway et al, 2002.
Selway JB, Smeds S-A, Cerný P, Hawthorne FC (2002) Compositional
evolution of tourmaline in the petalite-subtype Nyköpingsgruvan
pegmatites, Utö, Stockholm archipelago, Sweden. GFF, 124(2):93–102.
last modified 18-Jun-2015