( ( ( A ( chemical test ) ) ( ( performed ( on ( ( a sample ) ( of ( ( ores or ) minerals ) ) ) ) ) ( to ( determine ( ( the amount ) ( of ( valuable metals ) ) ) ) ) ) ) ( contained . ) )
(ROOT (S (NP (NP (DT A) (JJ chemical) (NN test)) (VP (VBN performed) (PP (IN on) (NP (NP (DT a) (NN sample)) (PP (IN of) (NP (NNS ores) (CC or) (NNS minerals))))) (S (VP (TO to) (VP (VB determine) (NP (NP (DT the) (NN amount)) (PP (IN of) (NP (JJ valuable) (NNS metals))))))))) (VP (VBD contained)) (. .)))
A chemical test performed on a sample of ores or minerals to determine the amount of valuable metals contained.
(ROOT (S (NP (JJ Ores) (NN rock)) (VP (VBZ contains) (NP (NP (NNS concentrations)) (PP (IN of) (NP (JJ valuable) (NNS minerals))))) (. .)))