so 
Tlic American Gcoloi^ist. 
July, 1902. 
ed. 
34 
Calculated. 
34 
55" 3^' 
24 
138 25 
51 
82 46 
lO 
4.S 
eral crystals. This form is always quite small. On one 
large crystal, the edges of which were very much rounded, the 
prism of the second order (100) could be easily detected. The 
faces of this form were quite large, but measurements could 
not be made with any degree of accuracy. A number of w^ell 
preserved crystals showed a twisting and contortion, which 
are so characteristic of quartz. This same phenomenon was 
observed by W. E. Hidden* on xenotime from McDowell Co., 
X. C. Figure I shows a combination of all the observed 
forms, namely: m (no), a (100), o (m), and p (331). In 
all nine crystals were measured. 
The results are as follows : 
Crystal system : Ditetragonal bipyramidal. 
Axial ratio : a : c = i : 0.6208. 
o 
(in) : (I'l'i) =+82" 34' 
(III) : (i_i_i) 55 
(331) : (331) 138 
(331) : (331) 82 
(100) : (no) 45 
The axial ratio as well as the various angles agree very 
closely with those of xenotime. Danat gives i : 0.61867 as the 
axial ratio for xenotime, while Grothi accepts i : 0.6177. The 
axial ratio of hussakite agrees much l^etter with the ratio 
given by E. Hussak^ for xenotime from the same locality, 
namely, Dattas. His figures are 1:0.62103, the difiference be- 
ing two units in the fourth decimal place. Likewise, the an- 
gles agree remarkably well with those observed by H. Gorceix° 
on crvstals, which he described as xenoti.r.e. 
The following table shows the great similarity between 
several of the angles of hussakite and xenotime. 
Hussakite Xenotime 
/ '^ 7-v 
Kraus: Dana: Hussak: Gorceix: 
(ill) : (ill) =82" 34' 82-22' 82" 15' 82" 30' 
(III) : (rn)=^-55 34 55 3° 55 ^^ 55 34 
As already mentioned, the crystals are generally trans- 
parent, especiallv when quite thin. When thick, translucent. 
'American Jovrnal of Science, Nov., 18!SS, 36, 380-383. 
tDana, System of Mineralogy, 1892, 74-8. 
$Groth, Tabellariscbe Vehersicht der Mineraliea, 1898, 84. 
^E Hussak, Tschermak's Mittheilungen, 1891, 12, 4-57. 
°H. Gorceix. Compt. rend. 1886, 102, 1024. 
