Lopaz. Bog 
“alkali, (which stain could not be removed without washing 
and thoroughly heating the foil,) not as deep however, in the 
case of the mineral under consideration, as with the spodu- 
mene. But the trial we made was not thorough; yet as we 
have not had leisure to pursue it farther, we merely make the 
suggestion that this mineral may contain lithia; and if so, it 
will account for the remarkable change from blue to green, 
which its powder produces upon vegetable infusions. The 
following are the collected results of the above imperfect 
irials. Fifty grains contain 
Water, - - - - - - - 1.43 
Alumine (B.No.IL.=13.2 gr.)+-(D No.I-=6.3 grs.) 93.73 
+-(C. No. If1.=0.9 gr.)+(D. No. Hi=3.33 grs.) § ~~" 
Silex (D. No.]I.=3.4 gr.)+-(D.No.1V.==:11.47 girs.) 14.87 
Fluoric Acid (B. No. IIT.) - - - - 4.56 
fron? Lithia? and loss, - - - Sir BD 
50.00 
After this examination we cannot hesitate to pronounce 
this mineral to be the topaz ; agreeably to your opinion ex- 
pressed upon first inspecting it. If this opinion be correct, it 
adds another interesting mineral to the list of American lo- 
calities, since, as we believe, no certain locality of the topaz 
has been announced in this country. ‘The enormous size of 
some of the crystals hitherto found does indeed detract from 
their delicacy and beauty, so that in these respects they will 
not compare with the topazes of the eastern continent. But 
we doubt not, finer crystals will ere long be disclosed. At 
any rate, it is certainly a very curious fact, that several of the 
rare minerals of Kurope, should occur in this country ona 
large scale, and in great abundance. For example, the 
beryls of Haddam, the spodumene and siliceous oxide of 
manganese of Massachusetts, the spinelle of New York, and. 
very especially the mineral which is the subject of this article. 
A crystal of the topaz, found in Aberdeenshire, which is sup- 
posed to be the largest ever seen heretofore, weighs but 
little more than seven ounces Troy, and the largest fragment 
but one pound; while two crystals aggregated in our posses- 
Sion, weigh, allowing for portions detached for examination, 
two anda half pounds, (much the greater bulk, however, is 
eccupied by one of the crystals, which by calculation must 
weigh about one pound and three quarters.) and a fragment 
two pounds and one ounce. 
