E. II. Kraus — Celestite- Bearing Rooks. 293 



amount of celestite is still present. Figures 3 and 4 represent 

 a specimen (two views) from Split Bock, a short distance west 

 of Syracuse, X. Y. In this specimen a very large percentage 

 of the rock was celestite, as is indicated by the large num- 

 ber of cavities. In the interior the mineral is still to be seen. 

 A comparison of these figures (3 and 4) with figure 1 shows 

 that a very close similarity exists between the two occurrences. 

 Figure 5 shows another "specimen from Jamesville, N. Y., 



where the celestite appears disseminated in small irregular 

 spots." 



A study of these and other specimens shows first, that the celes- 

 tite is or was actually distributed throughout the rock, or in 

 other words, imbedded in the rock ; second, that the cavities, 

 which remain after the mineral has been removed by solution, 

 conform for the most part to the original outline of the celes- 

 tite : and thirdly, that many of these cavities are very sharply 

 defined, being bounded by smooth surfaces. Therefore, the 

 conclusion is forced upon one that the celestite icas no doubt 

 deposited simultaneously v:ith the rock material, and also that 

 as the crystals of celestite formed, the soft rock material yielded, 

 and surrounded them on cdl sides. Such occurrences may, 

 hence, he considered of primary origin. 



Further investigations as to the crystallography of the celes- 

 tite in these localities, the amounts of the mineral actually 

 present in the rocks and the origin of the sulphur which is 

 associated with the celestite, especially at the Woolmith quarry, 

 are in progress in this laboratory and will be reported upon as 

 soon as feasible. 



I am indebted to Dr. G. P. Burns for the photographs 

 which accompany this paper. 



Mineralogical Laboratory, University of Michigan, 

 Ann Arbor, Mich., January, 1905. 



* Compare figs. 1, 3, 4, 5 with those shown in a previous paper "The 

 Occurrence of Celestite near Syracuse, N. Y., etc.," this Journal, lviii, 31, 

 33, 34, 1904 ; fig. 2 is repeated from that paper. 



