Fes, 1900. . NEw MINERAL OCCURRENCES—F ARRINGTON. 227 
exceed one millimeter in the direction of greatest length. They are 
colorless and transparent and remain so with the exception of a 
slight deliquescence on exposure to air. In distilled water, however, 
they turn white and in a short time become pulverulent from solution 
of sodium carbonate. The crystal forms are well developed and the 
faces fairly sharp and bright. In habit the crystals are somewhat 
different from any heretofore described on account of the relative 
subordination of e (o11) and the relative greater prominence of r (112) 
and ¢ (oor). 
The following forms were found : 
c (oor), m (110), ¢ (o1t), 7 (112). 
They were identified by the following measurements : 
apne san Limits. Observed. Calculated. 
MIRE IOL PIO. a's 50 < 5 Pilon AG wi tte Te pe liOe SO. 111° 10! 
ee OraT RIO. wich ss wis 2 83° 25'- 83° 30' 83° 30' 83° 30' 
Mee TOOT 2. cia ees. 2 43° T3—"43° 20' g eae rel 43° 20’ 
cae 3.2) le) rr 7 54° 10’— 54° 52’ 54° 45’ 54° 45' 
ere’ S011: O11... :..... 6. 5 108° 59'-109° 23’ TOO. 23: 109° 30’ 
yo PHTI2 112... ee eee 2 69° 34’ 69° 34’ 69° 29' 
Wem eee COOL Ls ono ccd hicie & 4 WEG iy CNS Mt A 42> 25. 1 Sele A i 
MIE SIOUL ETD). cass ee: 4 oy lly Ny ew Ley oy Poe 27 4al 
Meee TION T 3; oes oaks es 2 aCe Beet yy Baus 10, Se het fek 
The accompanying figure (Fig. 4) shows the usual development 
of the crystals. This development was quite constant for all that 

Fic. 4—Gay-lussite. Fic. 5—Gay-lussite. 
were examined. Fig. 5 shows the same forms in horizontal projec- 
tion on the plane of the clinopinacoid. Here is better shown, too, the 
relative greater length of the crystals in the direction of the clinodi- 
agonal axis. The faces of the prism m (110) are usually duller in 
lustre than the others, and the basal plane ¢ (oor) is often striated 
parallel to the edge cr. 
