ZIRCONIA. 
381 
zoned appearance around the terminations. One of these being accidentally broken, I found 
a rounded mass of white carbonate of lime in the centre, occupying nearly the whole interior, 
while the faces were all perfect, and indeed quite highly finished. Whether this is in all 
cases the cause of the parti-coloured appearance of these crystals, I am unable to say, but it 
is more than probable that such is the case. The fact is curious, as showing that the pre¬ 
sence of foreign bodies does not necessarily present any obstacle to the process of crystal¬ 
lization. Similar appearances are presented in the crystals from Johnsburgli. Some of these 
crystals also have been broken, and the terminations moved from their original situation, as 
shown in the figures given by Dr. Emmons in his report, and which he has obligingly per¬ 
mitted me to introduce. Fig. 431 exhibits the appearance of the broken crystals of zircon; 
Fig. 432 represents a bent crystal of apatite, associated with the zircon. 
Fig. 431. Fig. 433. 
Warren County. The largest and most interesting crystals of zircon heretofore found in 
this State occur at Johnsburgli in this county. One of these is a modification of the dioctae- 
Fig. 433 . dre of Haiiy, Fig. 433 ; and 
to this may be added the 
forms given in Figs. 434 
and 435; and those repre¬ 
sented in Figs. 415 and 418. 
The measurements have al¬ 
ready been introduced, and 
need not be repeated. 
All the figures from the 
preceding locality have been 
drawn from specimens in 
the Cabinet of Dr. Emmons. 
The crystals were from half 
an inch to three-quarters of an inch in length, and from a quarter to half an inch in diameter, 
with all the planes perfect, and often very highly finished. They are of a reddish brown 
colour, with usually a lighter central portion as in the specimens from Hammond in St. Law¬ 
rence county, and are opaque or feebly translucent. 
