G. P. Merrill — Free Gold in Granite. 



311 



without a trace of iron staining and with no cavities left by 

 pyritiferous decomposition (see tigs. 1 and 2). 



Fig. 1. — Free gold in feldspar 



Fig. 2 — Free gold in quartz. Gold indicated in black. 



The Museum has no record as to the occurrence of this ore. 

 But if, as is apparent, it is a normal granite, the occurrence is 

 of importance in its bearing upon the question of the origin of 

 the gold in veins and other secondary deposits. 



National Museum. Mar. 2, 1896. 



Supplementary Note. — Since the above was in type the 

 writer's attention has been called by Mr. W. Lindgren to an 

 article by W. Moricke (Tschermak's Min. u. Petr. Mittheil. iii, 

 1891) on Chilean ore deposits, in which free gold is described 

 as occurring in a quartz-trachyte. The metal is visible with 

 the aid of the microscope and is found both in glassy (pech- 

 stein) and crystalline varieties. It is regarded by Moricke as 

 an original constituent. 



