184 PROCEEDINGS OF THE ACADEMY OF [Part I 



Table 3. Analyses of Albite and Oligoclase, Unionville, 



Chester County, Pa. 



A. Albite, white; mean of two analyses. J. L. Smith and George J. Brush, 

 Am. J. Sci. (2), 15:211, 1853. 



B. Albite, white, crystalHne. Martin H. Boye, Proc. Am. Phil. Soc. 2: 150, 

 1841. 



C. Albite, white, crystalline; analysis by Weld. Benjamin Silliman, Jr., 

 Am. J. Sci. (2), 8: 377-394, 1849. 



D. Oliogoclase, brownish-white; analysis by Thomas M. Chatard. Frederick 

 A. Genth, Proc. Am. Phil. Soc, 13: 361-406, 1873. 



A B C D 



Si02 64.27 



AljOa 21.21 



FejOa tr. 



MgO 0.58 



CaO 0.81 



NajO 10.94 



K5O 1.36 



Ignition 1.08 



100.25 

 Sp.gr ' 2.61 



LOCALITIES OF PLUMASITE IN OTHER STATES. 



Pelham, Massachusetts: The occurrence of corundum and 

 its associated minerals at Pelham, Mass. has been described by 

 Emerson. 2^ The locality is an asbestos mine, one mile southwest 

 of Mount Lincoln, Pelham township, where a great block of black 

 saxonite is enclosed in Pelham granite gneiss. 



The saxonite is a fine granular dark gray rock composed of color- 

 less enstatite darkened by abundant chromite and magnetite, and 

 containing porphyritic plates of bronzy enstatite. Between the 

 Pelham granite gneiss and the saxonite a thick contact ''reaction 

 rim" has been developed. The granite gneiss is a light gray rock 

 consisting of a granular mixture of quartz, microcline, streaked 

 with biotite scales and epidote grains. Near the contact the gra- 

 nite is more massive, less biotitic and quartzose, and grades into 

 a layer of snow-white, fine grained anorthite containing some an- 

 desine crystals, and much disseminated tourmahne, rutile, zircon, 

 and allanite. This layer passes into an interrupted layer of black 

 massive tourmaline in many places two feet thick, at times con- 

 taining some large imperfect crystals of the mineral, with small 



="*U. S. Geol. Surv. Monograph, 29: 47-55, 1898; U. S. Geol. Surv. Bull., 

 597, 215-216, 1917. See also Earl V. Shannon, Am. Min., 4: 37-39, 1919. 



