JUNE 4, 1923 SCHALLER: A NEW SILVER-MINERAL 933 
MINERALOGY.!—Argentojarosite, a new silver mineral. (Pre- 
liminary note.) Watprmar T. ScHALLER, Geological Survey. 
The name argentojarosite is given to a new silver mineral from the 
Titanic Standard mine at Dividend, Utah. It forms small hexagonal 
scales of a yellow to brown color, and optically is uniaxial, negative. 
The mineral closely resembles jarosite, and in fact has been mistaken 
for it. In composition the new mineral conforms to the general for- 
mula of the minerals of the jarosite group and the mean of several anal- 
yses shows that its composition is about as follows: Ag.O, 18 per cent; 
Fe.O3, 43 per cent; SO;, 28 per cent; H,O, 10 per cent. A little K,0 
is present, also some PbO. This composition yields the formula: 
Ag,O: 3Fe,0;-450; 6:0. 
The mineral apparently is sufficiently abundant to be ae as an 
ore. It is the first silver mineral recorded containing oxygen. A full 
description of argentojarosite is in preparation. 
1 Received May 16, 1923. 
