( ( ( A polymorph ) ( of ( the ( mineral diamond ) ) ) ) ( ( is ( the ( mineral graphite ) ) ) . ) )
(ROOT (S (NP (NP (DT A) (NN polymorph)) (PP (IN of) (NP (DT the) (NN mineral) (NN diamond)))) (VP (VBZ is) (NP (DT the) (NN mineral) (NN graphite))) (. .)))
A polymorph of the mineral diamond is the mineral graphite.
(ROOT (S (NP (DT A) (JJ synthetic) (NN diamond)) (VP (VBZ is) (RB not) (VP (VBN considered) (NP (DT a) (NN mineral)) (SBAR (IN because) (S (NP (NNS minerals)) (VP (MD must) (VP (VB be) (VP (VBN created) (ADVP (RB naturally))))))))) (. .)))