_ examined some of these species in more detail. The material in 
to be hexagonal, Its indices of refraction are w = I1. 558, t= 
370 The American Naturalist. 
They remain unchanged in the air, and have the same compositi 
amarantite and the specimens of hohmantite ® analyzed a short | 
since,—viz., Fe,S,0,+7H,O. Various other minerals from thes 
region are briefly alluded to in this paper, and two new ones (quete 
and gordaite)"™ are described. Messrs. Genth and Penfield " 
possession is from the Mina de la Campania, near Sierra 
Amarantite is found to be ruai with @: 5: ¢==.76915: 1: 9 
&@— 95° 38 16", B= 90° 23' 42”, y= 97° 13' 4”. The habit oF 
crystals is prismatic. The brachy, and macropinacoids are verti¢ 
striated, and a perfect cleavage is parallel to each. The optical a 
= 63° 3’, and the extinction in the macropinacoid is 16°=1 
acute, Fibres of sideronatrite show a slight pleochroism, with a 
straw-yellow color parallel to the longer axis, and no color at 
angles to this. The formula ascribed to the substance differs esi 
Frenzel’s formula in lacking one molecule of water. Ferronal i 
although obtainable only in white or grayish cleavage masses, is th g 
and its composition is SO,=.51.30; Fe,O, = 17.30; NaO = 1 
H,O = 11.89 ; specific gravity = 2.547—2.578. Darapsky ” also 
a few notes of observations on a few of the minerals from A 
Among these are aromite, paposite, amarantite, hohmannite, coquit 
aragonite after calcite, from Miisen in Siegen, is one of the few in 
described in which the latter mineral is known to have changed i 
the’ ayi and subsequent deposition of calcium cz 
calcium-bearing solutions containing traces of barium. By € other 
tation Bauer has found that barium bearing calcium c 
-° Miner. u. Petrog, Mitth., IX., p. 397. 
Hiei Gone ie aa 1860, 1 “oD. 40. 
TE PAANS Mia. etc., 1890, I., p. ro. 
