MINERALOGICAL NOTES. 
57 
MINERALOGICAL NOTES. 
By A. K. Coomaraswamy, B.Sc., 
Director , Mineralogical Survey of Ceylon. 
I.—The New Mineral. 
TN 1903 Mr. W. D. Holland (who has long taken an interest in 
the mineralogy of the Bambarabotuwa district) obtained a 
quantity of a heavy black mineral occurring in cubic crystals, 
which he naturally identified as uraninite (pitchblende). Samples 
were sent to Sir W. Crookes, Sir W. Ramsay, and others, and the 
whole amount available (some 5 cwt.) was purchased by the latter 
chemist. Samples were also sent through the Mineralogical Survey 
to the Imperial Institute for examination and analysis. 
In a letter published in Nature , p. 510, March 31,1904, Professor 
Dunstan published the following analysis of two samples, made 
by Mr. G. S. Blake at the Imperial Institute :— 
I. 
II. 
Th 0. 2 
... 76-22 
Th 0 2 
... 72-24 
Ce 0 2 
|... 8-04 
Ce 0 2 
... 6-39 
La 2 0 3 , Di 2 0 3 
La 0 3 Di., 0 ;! 
... 0-51 
Zr 0 2 
... trace 
Zr O. 
... 3-68 
u 0 3 
... 12-33 
U0 3 
... 11-19 
Fe 2 0 3 
0-35 
Fe 2 0 3 
... 1-92 
Pb O 
2-87 
i PbO 
... 2-25 
Si 0 2 
... 012 
Si 0 2 
... 1-34 
Insol. residue 
* ... 0-41 
99*93 
99-93 
S. gr. 
... 9-32 
S. gr. 
... 8-98 
These analyses showed that the mineral was not pitchblende, 
and Professor Dunstan suggested the name of thorianite for the 
new mineral. 
In a letter in Nature , p. 533, April 7, 1904, however, Professor 
Ramsay published the preliminary results of his examinations, 
stating that a much smaller percentage of thorium occurred in the 
mineral, and that no appreciable amount of cerium, lanthanum, 
and didymium entered into its constitution ; but the presence of 
one or more new elements was indicated. The mineral was 
strongly radio active, but contained only a trace of radium, the radio¬ 
activity due to this source being certainly not 5 per cent, of the 
8(3)04 * * x 
