W. G. Mixter on Willemite and Tephroite. 231 
Great care was taken to ensure the complete separation of the 
different bases and the purity of the different precipitates, 
of zine as ammonio-phosphate and weighed as pyro-phosphate. 
; 
7 Two analyses gave:— 
a x 2. Mean. Oxygen. 
Mm Silica _...-_-.__ 27°48 = - 27°86 2740 1461 14°61 
: finc-oxyd, roe 66°83 tes 66°83 13°19 
Manganousoxyd, 5°69 5°78 5°73 1:29- 14°49 
Ferrous oxyd,_.. 0°06 0-06 0°06 01 
Magnesia, ---. _- trace trace trace 
gnition, ...____ 18 0°18 0°18 
100°19 100°20 
Il. Honey-yellow Willemite.—This variety occurs in hexag- 
onal crystals with rhombohedral terminations imbedded in the 
highly crystalline and cleavable limestone as well as sometimes 
intimately associated with the zincite and franklinite. The 
specimen selected for analysis was translucent, almost trans- 
parent, of a honey-yellow color, and formed the interior of a 
crystal an inch or more in diameter, which exteriorly was of a 
. yellowish to flesh-red color. The mineral was entirely free 
many traces of franklinite or zincite. Specific gravity =4:11. 
Hardness=5'5. B.B. same as No.1. Analyses conducted as 
before described, gave 
" 4 sk 2. Mean. . Oxygen. 
a 27°75 28-09 97°92 14:89 14:89 
ee eereoryd, | 58°05 57°62 57°68. 1142 
_ Manganousoxyd, 12°62 12°57 12°59 2°84 1 436 
Ferrous oxyd,-.. 0-49 0-74 0°62 14 
: Hlagnesia, -___ 196) 6) 114 46 
a MO -20-28 0°28 0°28 
100°34 100°42 100°38 
IIT, Ash-gray mineral.—tT his variety is found at the north 
Mine Hill. me specimens show a distinct cleav- 
one direction, while on others, little or no cleavage can 
0 
reached until it was analyzed. It occurs in large mases, 
= 
‘+. B.B. the mine @ TUsiDis 
n green and honey-yellow willemite, and instead of yielding 
* By a typographical error, the specific gravity of the magnesian tephroites 
| Mhese) oie 
