| 1887] Mineralogy and Petrography. 1025 
: The specific gravity of the metallic acids (5.769) is too high for 
tiobic acid, while no tantalic acid was detectable by Rose’s 
to suppose that it is not crystallographically identical with 
_heulandite, as Des Cloizeaux found it to be in its optical proper- 
tes ——Rutile—The rutile crystals occurring in the spodumene- 
bearing pockets of the gneiss in Sharp’s township, Alexander 
County, N. C., are described by Messrs. Hidden and Washing- 
tl 
On all the beryl from this locality it was observed that 
m face œP is perfectly smooth, while œP2 is covered with 
S ‘angular pits. ; l 
ted the Occurrence of the plane oP# on the alternate prismatic 
ay developed in each consecutive prismatic edge.——1. opaz. 
poo crystal of topaz+ from Zacatecas, Mexico, contains the 
, —~ Waters of the Yellowstone National Park. ne ie 
~ Occurs as a green coating covering the siliceous sinter Ce- 
Tee : 2 Amer. Jour. Sci., xxxiii., 1887, p- 501- 
G. yasta., xii., p. 456. 4L. c. 
Septem) wiams, Amer. Jour, Sci., Oct. 1887, p. 275- 
~~ B37 p. ry. 
