Document LKRwkjMZrwpYNMg5MZdYyNgBq

FILE NAME: RT Vanderbilt (RTV) DATE: 1989 July 28 DOC#: RTV089 DOCUMENT DESCRIPTION: Letter from Univ of Maryland to RT Vanderbilt Co. Starting Fibrous Talc Does Not Contain Asbestos )V THE UNIVERSITY OF M ARYLAND D r. C .s . Thompson COLLEGE PARK CAMPUS Deportment Of Geology R .T . V a n d e rb ilt Company, In c . 30 W in fie ld S t r e e t Norwalk/ C o n n e c tic u t 06852 J u l y 28, 1989 Dear D r, Thompson, I have examined the sample o f Mouldene(S-158) which you sent t o me on J u l y 1 9 , 1 9 8 9 . The m a t e r i a l c o n s i s t s p r im a r ily o f fib r o u s t a l c w ith sm a ll amounts o f tre m o lifce , an th o p h y llite , ca rb o n a te , q u a r tz , p la ty t a lc and fe ld s p a r . The fib r o u s t a l c o c c u rs in f i b e r b u n d les w ith sp lay ed ends and as what appear to be in d iv id u a l f i b e r s . The in d ices of r e fr a c tio n of th is m aterial are h igh ly v a r ia b le ,. P a r a lle l to e lo n g a t io n , )( ranges from 1.594 to 1 .5 7 6 ; how ever, most o f the f i b e r s and f ib e r b u n d le s have J f ' s betw een 1.5 8 2 and 1 .5 8 8 . P e r p e n d ic u l a r to e lo n g a tio n th e in d ic e s o f r e f r a c t io n are much more v a r ia b le , ra n g in g from 1.536 to 1 . 5 7 8 . These v a lu e s re p r e s e n t the range in o( and $ . In g e n e r a l, th e more th e f ib e r s d is p la y the c la s s ic a l ch a racteristics of asbestos, i . e . , fiber b u n d le s' w it h s p la y e d ends, sm all f i b r i l width, curved f ib e r s ,e t c .' , the lower are the in d ic e s o f r e fr a c tio n w ithin the ranges given above, , The a n t h o p h y l l i t e does not d is p la y asb e stifo rm d h a r a c t e r is t ic s . I t is most e a s ily recognized by i t s p e cu lia r s trip e d e x tin c tio n p a tte rn which a ls o appears to be r e fle c te d in p la in lig h t as variable in d ices of r e fr a c tio n . These c h a r a c t e r i s t i c s m ight be e x p l a i n e d as an in te rgro w th of a n th o p h y llite and t a l c . ^ fo r a n th o p h y llite is always greater th an 1.600 w h ile c< was measured a s 1 .5 9 6 :, ' T r e m o lite , l ik e a n t h o p h y llit e , does not d isp lay the ch a ra cte ristics of asbestos. I t is gen erally blocky, but an o c c a s io n a l p a r t ic le has an a s p e c t r a t io in excess o f 1 0 :1 . 0( f o r t r e m o l i t e was measured as 1 . 6 0 0 , and fo r tr e m o lite is greater than 1.600. T re m o lite and a n th o p h y llite are ab o u t e q u a lly abundant, T ogether th e y t o t a l 5-10% o f th e sam p le. A few p e r c e n t o f the sample i s ca rb o n a te , a l i t t l e le s s is q u artz and fe ld sp a r occurs only in tra ce q u a n titie s . I f you have any q u e s tio n s , p le a s e l e t me know. Sin cerely yours, Ann G , W ylie College Park. M aryland, 20742 (301) 464-3548 WES000751