Natural Sciences of Philadelphia 
3 
Special Reports by Members of the Scientific 
Staff Based on Recent Explorations Con- 
ducted in the Interests of the Academy. 
MINERAL COLLECTING IN THE ANDES. 
(The Vaux-Academy Andean Expedition of 1921) 
By Samuel G. Gordon. 
It was the writer’s privilege to make a trip through the Andes 
from Ecuador to Chile during the summer and autumn of 1921. 
The expedition was made primarily to secure mineral specimens 
for the William S. Vaux Collections in the museum of The Academy 
of Natural Sciences of Philadelphia, and to obtain material for 
crystallographic research in the laboratory of the Academy. 
Incidentally a collection of Andean rocks of much interest was 
secured. As the scientific results will be published in a series of 
mineralogical and petrographic papers in the Proceedings of the 
Academy, the present account covers merely the itinerary and obser- 
vations of general interest made during the trip. 
The South American Cordilleras, aside from their scenic beauty, 
present much of interest to the traveller who desires to delve 
into their scientific aspects. To the geologist, the structural 
features of the great mountains and the volcanic phenomena 
manifest in many parts of the Andes, present problems whose 
study form attractive field; and in no less degree alluring to the 
mineralogist are the interesting mineral species which have been 
discovered in the various Andean mines, many of them of un- 
usual composition, or crystal form. 
