Rossmanite was found in a lepidolite subtype pegmatite dike at Radkovice. It occurs with other members of the tourmaline group (schorl, and elbaite) and is found in the K-feldspar zone and in the lepidolite core.
Composition:
References:
Selway JB, Novák M, Cerný
P, Hawthorne FC (1999) Compositional evolution of tourmaline in
lepidolite-subtype pegmatites. European Journal of Mineralogy,
11:569-584.