(S (S (S (NP (BASENP (DT The) (NN area) (POS 's)) (NNS minerals)) (VP (VBP have) (VP (VBN been) (VP (VBN disputed))))) (SBAR (RB ever) (SBAR (IN since) (S (BASENP (NNP Bridges)) (VP (VP (VBD discovered) (BASENP (DT the) (ADJP (RB locally) (JJ unique)) (NN stone) (NNP Tsavorite))) (PP (IN in) (BASENP (DT the) (NNS 1960s)))))))) (PERIOD .))