We determine when a class in
the Schur subgroup S(K) of the Brauer group B(K) of a field K of characteristic
zero contains an algebra which is isomorphic to a simple summand A of
the group algebra FG for some finite group G, where F is a subfield of K.
We then investigate A ⊗FK which is the direct sum of simple algebras
with center K, and determine exactly when these are K-isomorphic. Finally
we refine existing examples in the theory of the Schur group, and obtain a
decomposition theorem for the related group of algebras with uniformly distributed
invariants.