320 Count de Bournon*s Description of 
varieties found in them, except that in which the edges only 
are replaced. 
Zircon . This substance is, next to the spinelle, that which is 
most frequently found in the sand of Ceylon. It is true, that it 
is generally in crystals of a very small size ; but these crystals 
often possess the most beautiful transparency, and they are of 
many different colours. To the colours already mentioned as 
belonging to them, I may add, that they are sometimes of a 
reddish purple, and sometimes of a pale blue. 
Lastly, if to the substances which have already been described, 
I add, that there are also some small scattered fragments, but 
in very inconsiderable quantity, of quartz, of felspar, of calca- 
reous spar, of a brownish yellow mica, and of attractable oxide 
of iron, I shall have enumerated all the substances that are 
found in the sand of Ceylon, in the state in which it is sent 
to us. I have always been astonished at not finding in it any 
of the peridot, which, as is well known, also comes from 
Ceylon : hitherto, however, I have not perceived the smallest 
trace of it. 
Of the various substances that have been here described, the 
spinelle is that which more particularly constitutes the sand of 
Ceylon, such as it comes into Europe; but it is natural to 
suppose, as I have already had occasion to observe, that the sand 
has been previously examined, and deprived of every substance, 
except those which are found by experience to be fit for the 
purposes of commerce. The other substances above mentioned, 
are not so constantly found in it, nor are they found always 
In any regular proportion. I have seen, for instance, some 
of this sand which did not contain an atom of perfect corun- 
