A 
= 
Sufplement to Dana’s,Mineralogy. 363 
Un this formula, the first member has th oxygen ratio 2: . the second 9:3, a 
wide dive ersity. Con: nsidering the a ratio of the bases and silica, w e ob- 
serve that this ratio, according e above, i 1s 24:67:12, or Asses: 2:1, which is the 
ratio in staurotide, as if the arte might possibly come under the e general fo ‘orm- 
ula (BS, R) Si i? a is remarkable that the crystalline form should be ere iden- 
tical with that of orthoclase, suggesting the idea of a pseudomorph,—against which 
view ae tha hardness of the mineral and its bright faces seem to i op- 
analyses) rtapdie g to wre I2, apaiti ataxity S707 a 8° ©. 
orange at 300° C. but resumes its yellow color on cooling. 
Tnwosmine [p. 19]—-Claus found palladium in the erg of the yi 
Ketruaurre [p. 341 pt er ae ig 
by D Forbes (Edinb. N. Ph. J., [2], 
+) Monoclinic, according to crys’ sooks 
obtained by Mr. Dahl at Arkeroen, Nor- 
way, [ 
+ lbs. ; 
Were rough and the ——- were meas- 
ured pd Bes the common goniometer. 
wire generally Ming 
(Sg.2). "G. =558 ut 60°F. Analys 
i Ti Al Be Ca Mn 
3133 28:84 808 052 1956 478 687 0-28 = 99-41 
a 15°06 1118 3875 082 556 he 152 0-06 
The analysis <a boven 5 with those of Erdmann and Scheerer. Taking the Ti 
as base, the 0 atio of the silica and bases is then 2:8, and the formula, Dr. 
Forbes — that of 
‘ may be (R3, ®) Si®, which is the same as sphene 
(These re ts afford = conglans onfirmation of the writer's conclusion respect- 
ing the. ion of the t aia in sphene, and also of his published view 
of Keilhaaite e A above formula been written as above ex 
cept by the writer age Journal, xviii, 180, and his Mineralogy, Dr. Forbes 
agrees with the writer in objecting to the 
pis th , and agrees I o-calle 
stico titanates and ilseectan teiates. The resemblance in formula between keilhauite 
ne is mentioned in this Journal and in the writer's This 
Porat paper adis:th the confirmation required by showing that the form is mono- 
clinic lik sphene ore than this, sre the paper does not i are nag’ 
angles are dads ike those of Seller accompanying figure 1 is drawn from 
the data ai foed by figures; the es is like that of jeodeng’ in the places 
referred to, chevaspoasing i tering of Dr. Forbes and of Brooke and Miller is 
here gen: 
2 3 -2 -1 x —2i res 
‘ ; 
; Se? eee B. & M. 
‘The follo’ 3 measured by Dr. Forbes ; ‘and ina — col- 
ioe are the soi 
"mn the correspo nding angles of spheue are given from and } 
Keilhanite. ar 8 B. and M. 
74 = 147° . ‘ - - (r:¢) na a 
~2:-1 = 149° é F iak ld - (t:2) 150°17 
ii: 25 — 125° “4 z PS mr ee 126° 26’ 
O: ti = 129° See es - {y:e) 119° 83 
2: J =153° 30 s ‘é a # (n : r) reese rn 
2: O=143° 30° x ee - “ (a: A ‘ae msi “a 
calculations O:T is given as 114° 25 = ; itis 
rom is giv ag 
. made by Mr. Hansteen, 
114° gi" a 42, while seis 189° 20 in sphen 
21’ in sphene; O: 5 ee feiakden.. "Tho form of 
[poner Focslicagragecs page apr RAE See the writer's Miny-ii, 
