Hiissakite. — Kraus and Reitinger. 53 
which the sulphuric acid has been extracted by the circulating 
waters in nature and thus converted into an orthophosphate. 
In order to determine whether or not this might be the 
case, we treated finely pulverized hussakite with a solution 
of sodium carbonate for a short time on the water bath. It 
was clearly shown that the sulphuric acid can, in this manner, 
be easily removed from the mineral; for after an hour's 
heating, the filtrate gave a very distinct reaction for sulphuric 
acid. No doubt the circulating waters in nature, which gen- 
erally give a weak alkaline reaction, may have acted on hus- 
sakite in a similar manner and in due time changed it to an 
orthophosphate. 
If this supposition be correct, it would be reasonable to as- 
sume that the opaque xenotime crystals are pseudomorphs 
of yttrium orthophosphate after hussakite, and that the partial- 
ly decomposed crystals must show a presence of sulphuric 
acid. 
In a sand from Banderia de Alello (Bahia) opaque crys- 
tals of a pyramidal habitus were found, which Dr. E. Hussak* 
determined and described as xenotime. Through the kindness 
of Dr. Hussak a larger quantity of this sand, which aside 
from xenotime also contains corundum, quartz, garnet, mona- 
zite, and other minerals, was placed at our disposal. The crys- 
tals of xenotime were carefully isolated and examined chemic- 
ally. On crushing them it was found that they were opaque 
and partly decomposed. The quantitative analysis gave a 
distinct reaction for sulphuric acid. The results of the quan- 
titative analysis of this "xenotime" from Bandeira de niello 
are as follows : t 
I. 
II. 
PoO, 
27.40 
27-35 
so. 
2.62 
2.74 
SiO, 
0.6.T 
0.59 
\ Y.O. 
Rsd, 
60.0^ 
59-87 
I Er„03 
Fe,03 
4-.S8 
450 
( Gd.,03 
Al,03 
1. 10 
1.22 
CaO 
2.51 
2.60 
MgO 
0.49 
0.41 
H.O 
0.34 
0.40 
99.72 
99.68 
•E. Hussak, Tschermak's Mitteilungea, 1891, 12, 457. 
f Recently Dr. J. Reitinger ( Analytische Untersuchunpren uber die natur- 
lichen Phosphate, etc., Munich, 1902. ) made another anaylsis of finer specimens 
from this same sand and found only l.l-i per cent SO3. 
