The present invention relates to a process to produce high purity strontium sulfate and strontium carbonate from subterranean brines. The present disclosure also relates to chemical precipitations of subterranean brines to isolate strontium from divalent cations, such as calcium and barium. Such precipitations include the use of sulfate and subsequent solids separations and washing of the precipitate. In a latter step in the strontium carbonate process, a metathesis reaction with a carbonate is performed upon the strontium sulfate to produce strontium carbonate while allowing optional recycling of the sulfate. An additional rinse with acid or water of the strontium sulfate may be performed prior to metathesis to increase the purity of the resulting strontium carbonate.