818 Dr. Davy on the Geology and Mineralogy of Ceylon. 
tions, and those of recent date, that gold and mercury are found in 
Ceylon. The result of my enquiries is, that this assertion is com- 
pletely erroneous. 
The poverty of the island in metals is not less remarkable than 
its richness in rare and valuable minerals. Most of the gems for 
which Ceylon is well known, were originally, I believe, imbedded in 
gneiss ; I say ‘believe,’ because as these precious stones are seldom 
, found in their native rock, we cannot say with certainty whence 
they are derived, but only conjecture whence, from the quality of 
the alluvium in which they are met with, and from the nature of 
the rocks adjoining. 
The minerals which I have discovered in gneiss, or believe to 
have been at one time contained in this rock, are the following : 
1. Belonging to the quartz family, I may enumerate quartz, iron- 
flint, and hyalite. Ceylon affords all the different variations of 
quartz, as rock crystal, amethyst, rose quartz, cat’s-eye, and prase, 
and I need not repeat, common quartz. Rock crystal occurs in 
great abundance, both massive and crystallized, of various colours, 
good quality, and in large masses. It is so common, particularly 
in the Kandian country, that its localities do not require to be no- 
ticed. The natives use it instead of glass in making spectacles; 
they employ it, too, for ornamental purposes, and in statuary ; there 
is a small well executed crystal figure of their god Booddo, in the 
great temple in Kandy. Amethyst also is abundant ; very beauti- 
ful specimens of this mineral are found in the alluvium derived 
from the decomposition of gneiss in Saffragam and other parts of 
the Kandian country. Rose quartz, which is common, is found, I 
believe, in the same ground as amethyst. Ceylon is remarkable for 
producing the finest cat’s-eyes in the world. The best specimens 
this singular mineral, that I have seen, have been found in. the 
