Geology and Mineralogy. 153 
TiO, trace, H,O 3°36, hygroscopic me 20°54 = 100° SI, giving 
the quantiv ‘alent ratio for R, R, Si, 8°735 : 8°842 : 17°788 
ks of Quincy south of Boston te Htookp ort, near es 
Ann, sine ast of Boston.—Mr. E. Wapsworts states that 
the Qu uincy syenyte consists chiedly ~ schlibelaae, quartz and horn- 
blende, and that the hornbieads is black to dark green in color 
feldspar and also in some sietth issemin inute ¢ opie oO 
danalite. The stone of the Rockport uate has been called by 
most writers syenyte; but Mr. Wadsworth states that at least 65 
per cent of it is micaceous and destitute of hornblende, —, hence 
true granite. But while the quarried rock is almos holly 
granite, there is some syenyte. The two are 80 ad that 
“they are geologically one and the same rock.” Besides ortho- 
Clase, quartz, and black mica, the last (referred to lepidomelane 
y Cooke), there are in some parts of the Rockport granite, the 
“ay als cryophyllite and danalite, first announced by Professor 
19. On Lonite, a new Mineral; by S. Purnett.—In the Plio- 
cene argillaceous lignite of Tone valley, Amador county, Califor- 
nia, a peculiar mineral, more or less pure, occurs in thin seams. 
The specimen examined by me was of what may be called the 
best quality. It isa firm Pats snaps oan substance of 
a brownish-yellow color. "As s from the mine, it contains 
about 50 per cent of water, ‘but when sbcinenirhly ‘air-dried it 
readily floats on water, ss specific gravity being about ‘90. It 
rapidly — water & 
low; fracture, fy ee ne. When pita water 
dissolves or suspends a portion of the clay in the mineral, Par- 
maid soluble in cold scokels more so in boiling ateobal, giving a 
