198 
do not know of any other having been found in Great 
Britain. It is of an intense semitransparent red, showing 
~ occasionally a brilliant reflection. The crystal is represented 
distinctly, and rather large, at the bottom of the plate, showing 
the principal faces deeply striated, with the bevelings, trun- 
cations, &c. The Quartz upon which it is found is rather 
elegantly crystallized and grouped; but could not be drawn 
with every advantage to show both subjects, and the white 
Adularia, which is in small crystals, somewhat like those 
in dabs. 211 and 212 in form, much resembling that found 
abroad, being nearly as transparent as the Quartz, which 
adds much to its rarity as being British. 
Oxide of Titanium when crystallized is said to contain 
little or no Silex. Its specific gravity is from 4°1025 to 
4°246. It is soft, but not easily scratched with a knife. The 
fracture in the present specimen is vitreous, nor could we 
discover any other, though Haiiy says its primitive form is 
an upright prism with square bases. The most conspicuous 
faces of the largest flat crystal on the specimen are shown 
in the lower figure, the three angles of incidence that could 
be measured were al, bc, cd; the first measuring 142°, the 
second 130°, and the third 147°. 
There are many minute irregular fragments about the 
gangue, and two crystals remarkable for being flattish in 
the pyramidal end of the large Quartz crystal, one of 
which is reflected three times, or seen at the same time in 
three of the faces, which serves as an exainple of the mul- 
tiplying quality of faceted subjects, very convenient in 
this where the substance is scarce. It is infusible by the 
blowpipe, but becomes blackish and opaque. 
Since writing the above, I have been presented with a 
superb specimen of Quartz, on which are two or three 
crystals of this Oxide of Titanium, by my kind patron the 
Right Hon. the Earl of Dartmouth, from the same place. 
This specimen also has some Adularia about it. 
