396 F. A. Genth — Contributions to Mineralogy: 



b. Axinite from Guadalcazar, Mexico. 



The material for examination was kindly presented by 

 Messrs. Geo. L. English & Co. The axinite is associated with a 

 white feldspar, in part altered to kaolinite ; it is found in 

 minute crystals, the largest not over o mm in size, and granular 

 scaly masses, the individual scales from l-2 mm . The color is 

 brownish to greenish gray of various shades (sage color). Spec. 

 grav. =3-299. 



These crystals are tabular parallel to the 

 pyramid r, 111, fig. 2. The faces are usually 

 curved and uneven and some of them are 

 striated, a and m parallel to their intersec- 

 tion and r parallel to the zone M r, so that 

 the crystals are not suited for exact measure- 

 ment on the goniometer. The following 

 forms were identified by measurements, 

 J/ which seldom varied more than half a degree 



^-±^ from the calculated. 



a, 100, i-i m. 110, F r, 111, -1 z, 112, — £ 



6, 010, i-i M, 110, / x, 111. -V 7, 131, 3-3' 



c, 001, s. 201, -2-i e, 111, 1' n, 131, -3-3 



Of these c, e and n, not represented in the figure, on most 

 of the crystals are either wanting or very small : s and x are 

 small and frequently wanting : the other forms are quite con- 

 stant, about as represented in the figure. 



The larger crystals did not yield very good material for 

 analysis as they are often too intimately mixed with feldspar ; 

 the granular variety however was in places almost pure, contain- 

 ing only traces of kaolinite from which it was easily purified. 



The analysis gave : 



Ignition = 0"75 



Si0 2 42-85 



B 2 3 5-17 



A1 2 0„ ... 16-96 



Fe 2 0° 3 5-00 



CuO 0-19 



MnO 9-59 



MgO 0-87 



CaO _ 18-49 



99-8' 



There were two minute crystals associated with this axinite, 

 one of white color in pyramids, apparently quadratic; the 

 other black, neither of which could be identified. 



