( Pleochroism ( ( is ( ( ( ( ( an ( optical property ) ) ( observed ( when ( ( the mineral ) ( is ( viewed ( under ( ( the microscope ) ( in ( plane ( polarized light ) ) ) ) ) ) ) ) ) ) ) , ) and ) ( ( when it ) ( ( ( the stage ) ( of ( the microscope ) ) ) ( is ( rotated ( the ( observed ( colors change ) ) ) ) ) ) ) ) ) . ) )
(ROOT (S (NP (NNP Pleochroism)) (VP (VBZ is) (SBAR (SBAR (S (NP (DT an) (JJ optical) (NN property)) (VP (VBD observed) (SBAR (WHADVP (WRB when)) (S (NP (DT the) (NN mineral)) (VP (VBZ is) (VP (VBN viewed) (PP (IN under) (NP (NP (DT the) (NN microscope)) (PP (IN in) (NP (NN plane) (NN polarized) (NN light)))))))))))) (, ,) (CC and) (SBAR (WHADVP (WRB when) (NP (PRP it))) (S (NP (NP (DT the) (NN stage)) (PP (IN of) (NP (DT the) (NN microscope)))) (VP (VBZ is) (VP (VBG rotated) (NP (DT the) (ADJP (JJ observed)) (NNS colors) (NN change)))))))) (. .)))
Pleochroism is an optical property observed when the mineral is viewed under the microscope in plane polarized light, and when it the stage of the microscope is rotated the observed colors change.
(ROOT (S (SBAR (IN Although) (S (NP (PRP it)) (VP (VBZ is) (NP (DT the) (JJS easiest) (S (VP (TO to) (VP (VB observe)))))))) (, ,) (NP (NN color)) (VP (VBZ is) (RB not) (ADJP (JJ ideal) (PP (IN as) (NP (DT a) (JJ sole) (NN way)))) (S (VP (TO to) (VP (VB identify) (NP (NNS minerals)))))) (. .)))