( as ( , ( ( ( a mass ) ( of ore ) ) ( , ( ( ( ( ( ( metal , ) sand ) , ) or ) water ) . ) ) ) ) )
(ROOT (FRAG (PP (IN as)) (, ,) (NP (NP (DT a) (NN mass)) (PP (IN of) (NP (NN ore)))) (, ,) (NP (NP (NN metal)) (, ,) (NP (NN sand)) (, ,) (CC or) (NP (NN water))) (. .)))
as, a mass of ore, metal, sand, or water.
(ROOT (S (NP (NNS Metals)) (VP (VBP start) (PRT (RP out)) (PP (IN as) (NP (NN ore)))) (. .)))
Metals start out as ore.