160 Decomposition of Iron Fyrifef<. 



Tkial oy PfKiTE Crystals By Vapor of Nitric Peroxide. 



g' 



8p. Form of 



1 

 Tarnish Efflorescence 



Nuclei of Pyrite 



t^i'l Locality. 



Or. crystal 



after | 



left undecom- 



"1 





tested. 



lU days. 



after 50 days. 



posed. 



3 



Marsden's 



1 

 5.023 Cube. 



Tarnish- 



Decom posed 



A few granules 





Diggings, 



1 



ed, with explosion 



and many fine 





111. 



1 



to grayish and 

 i white powder. 



splinters." 



8 



Alabama, 



5.011 Cube. 



Tarnish- Like No. 17. 



Large grains. 





N. Y. 



1 



ed. 







10 



Gilpin Co., 



5.011 :Pyrito- 



Bright 



A mere yellow- 



No trace of dis- 





Col. 





hedron. 



as ever. 



ish film, with- 

 out powder; 

 form perfect. 



integration. 



17 



Pinal Co., 



5.007 ;Cube. 



Bright 



About i al- 



Two large 





Ariz. 







as ever. 



tered to yel- 

 lowish white 

 powder: form 

 retained. 



grains. 



31 



French Cr'k, 



4.997 Octahe- 



Bright. 



AVhite vitriol. None. 





Pa. 



1 dron. 





stained red- 

 dish external- 

 ly : form re- 

 tained. 





39 Bristol, Ct. 



4.993 Cube. 



Tarnish AVhite and gray One crystal 









ed. 1 powder; form' merely crust- 









1 retained. 



ed with vitriol. 



41 



Gt. Barring- 

 ton, Mass. 



4.991 Cube. 



Bright Like No. 17. 

 as ever. 



Large grains. 



46 



Roxbury, 



4.985 Cube. 



Bright. Decomposed Some grains 





Mass. 



i 



with explo.sionj and many fine 

 \ to bulky gray- splinters. 

 ' ish and brick- 

 red powder. 



51 



St. Lawrence 



4.970 Cube. 



Tarnish- 



Deco m p s e d None. 





Co., N. Y. 



' 



ed. 



to abundant 

 white powder 1 



55 



Guanajuato. 



4.954 Cube. 



Dulled 



Soft gray and 



A few granules. 





Mex. 





lustre. 



white powder. 





62 



Franconia, 



4.941 Cube. 



Tarnish- 



Mostly to a 



A few granules. 





N. H. 





ed. 



white powder, 

 with some 

 waxy yellow 

 flakes. 





71 



Weehawken, 



4.919 Octahe- 



Tarnish- 



Yellow'h white 



A few tarnish- 





N. J. 



1 dron. 



ed. 



powder, part- 

 ly grayish. 



ed particles. 



91 



Mahanoy 



4.905 Cube. 



Dull tar- 



About ^ decom- 



Large grain. 





City, Pa. 





nish. 



posed, with ex- 

 plosion, to soft 

 graj^ powder, 

 in parts white 

 or black. 





96 



Somerville, 



4.843 Cube. 



Dull tar- 



Deco m p s e d One cube mere- 





Mass. 







nish. 



to abundant ly encrusted 

 powder, as in with vitriol. 











No. 3. 1 



