144 schaller: gem tourmalines 



All of these minerals were found at Pala, San Diego County, Cali- 

 fornia. 



Palaite. 1 Probably monoclinic. A flesh-colored hydrous man- 

 ganese phosphate, resulting from the alteration of lithiophilite. 

 D. 3.14 — 3.20; mean refractive index about 1.655, slightly lower 

 than that of hureaulite; double refraction low. Forms crystal- 

 line masses in the cavities of which are found distinct crystals. 

 In thin section colorless, and non-pleochroic. Formula 5MnO. 

 2P 2 5 .4H 2 0, (Analysis 1). It alters to hureaulite. Found in 

 the Stewart Mine at Pala, from which the name of the mineral is 

 derived. 



Stewartite. Probably triclinic. A hydrous manganese phos- 

 phate from the Stewart Mine, after which it is named. It is 

 very abundant as an alteration product of lithiophilite which it 

 replaces along its cleavage cracks. The first formation of stew- 

 artite is in fine fibers arranged normal to the cleavage cracks of the 

 lithiophilite. Irregularly bounded areas and minute but distinct 

 crystals of stewartite were also noted. The crystal form and opti- 

 cal properties of these minute crystals serve to characterize the 

 mineral and to show that it cannot be identified with any known 

 species. Altho abundant, it is so intermingled with the other 

 minerals of similar composition that a pure sample of it, sufficient 

 for quantitative analysis, could not be obtained. Its importance 

 in the alteration of lithiophilite necessitates a name for the mineral 

 which its physical properties suffice to establish. D. 2.94. Mean 

 refractive index about 1.65. Double refraction very high, prob- 

 ably not under 0.05. Pleochroic: colorless, pale yellow, yellow. 

 Extinction inclined on all crystal edges. Axial angle large, nega- 

 tive, dispersion strong. Probably the same as the unknown 

 mineral "A" described by Lacroix. 2 



Salmonsite. Named after Mr. Frank A. Salmons, formerly of 

 Pala, and found in the Stewart Mine. It results from the par- 

 tial oxidation and hydration of hureaulite, and forms cleavable 

 masses of a buff color, seamed by small veins of fibrous palaite 

 and sprinkled with small masses of blue strengite. D. 2.88. 



1 Pronounced Pa-la-ite. 



2 Lacroix, A. : Mineralogie de la France, 4: part 2, p. 506. 1910. 



