( ( described ( as ( mineral fibers ) ) ) ( , ( ( ( a group ) ( including ( ( many forms ) ( of ( ( naturally occurring ) rocks ) ) ) ) ) ( ( like talc ) . ) ) ) )
(ROOT (S (S (VP (VBN described) (PP (IN as) (NP (NN mineral) (NNS fibers))))) (, ,) (NP (NP (DT a) (NN group)) (PP (VBG including) (NP (NP (JJ many) (NNS forms)) (PP (IN of) (NP (ADJP (RB naturally) (VBG occurring)) (NNS rocks)))))) (VP (VBP like) (ADJP (JJ talc))) (. .)))
described as mineral fibers, a group including many forms of naturally occurring rocks like talc.
(ROOT (S (NP (DT A) (NN mineral)) (VP (VBZ is) (VP (VBN described) (PP (IN as) (NP (NP (DT a) (JJ natural) (NN substance)) (SBAR (WHNP (WDT that)) (S (VP (VBZ makes) (PRT (RP up)) (NP (NNS rocks))))))))) (. .)))