126 Pratt— Miner alogical Notes from North Carolina. 



Art. XVIII. — Miner alogical Notes on Cyanite, Zircon, and 

 Anorthite from North Carolina; by J. H. Pratt. 



1. Cyanite. — The mineral to be described occurs on the 

 farm oi Tiel Young, near North Toe River, Yancey Co., 

 North Carolina, a few miles from Spruce Pine, Mitchell Co. 



Some exceptionally large crystals of a grass-green color were 

 obtained by the author during the summer of 1896 from Mr. 

 M. Alexander, a jeweler in Asheville. After some difficulty 

 the occurrence was located, during the past summer, and the 

 locality has been thoroughly worked by Geo. L. English & Co. 

 of New York, with the result that many good crystals of the 

 cyanite have been obtained. 



The mineral occurs in a decomposed mica schist from which 

 the single crystals are easily separated. The crystals are often 

 intergrown and masses of these were obtained as large as one's 

 two lists. All of the crystals found were of a rich grass-green 

 color and many were quite transparent. A few of the crystals 

 showed a deep blue center with the grass-green margins. The 

 crystals vary in size from lX'7 cm to 3*2x6 cm ; a few coarser 

 ones were observed that were considerably larger. The faces 

 are generally smooth, giving fair reflections of the signal on the 

 reflecting goniometer. 



The forms observed on these crystals are as follows : 



c, 001 a, 100 M, 110 



b, 010 m, 110 Q y 120 t, 520 



The face 520 is apparently a new one for cyanite. The 

 three pinacoids were the only faces observed on the majority 

 of the crystals, some of which were doubly terminated. After 

 a very careful examination of the terminations, they were 

 decided to be real basal planes and not cleavage surfaces. On 

 one of the crystals, all of the faces observed were developed. 



The following table shows the identification of the forms by 

 calculated and measured angles. In obtaining the calculated 

 angles the elements given in Dana's Mineralogy (1892), de- 

 duced from Path's measurements'* on Greiner crystals, have 

 been used. 

 a:b:c — 0-89938: 1 : 0-70896; a = 90° 5%' ; /?=101°2j'; y=105°44|-' 



Calculated. Measured.. 



a/^m, 100/U10 84° 17' 34° 1 V ; 34° 20' ; 



a^M, 100^110 48 18 48 43 ; 48 41 ; 48° 45' 



a^ Q, 100^120 48 43 48 50 



a^ t, 100^520 IV 9 11 13 



a/s b, 100^010 73 56 73 40 ; 73 38 ; 73 42 



b^M, 010/^110 57 46 57 41 



*Zs. Kr., v, 17, 1880. 



