OF CORNWALL. io 5 
the higheft hill in Cornwall according to my eftimate *. It is alfo 
found in our mines, but feldom ; the only one I have feen was 
taken out of a mine, called Huel-royal, in Camborn ; it was quite 
ovular, half uncovered and half fixed in a focket of angular and 
puculated cryftal ; one inch and half long, and one inch and one- 
fifth wide . but our white pebbles are moftly of an opake white 
quartz. 
N°. 2. Of the yellow kind our pebbles are ufually of a high 
polifh and amber-like fubftance, differently clouded, veined, or 
Spotted, with other colours. 
N°. 3 - Pebbles of a green ground are rare with us, none which I 
have met with tranfparent; in fome the willow-green is charged with 
pale-yellow crystalline granules, the charge prominent, Shewing that 
it is of a harder firmer confiffence than the ground. 
N • 4 * Or the ruddy ground fome of a faint lake-colour have 
large irregular granules of opake white quartz funk in them, 
thereby approving themfelves Softer than the ground. 
Of the brown-red fome are of a high polifh, fine texture, 
clouded with red interfered by a blackifh vein, plainly of the 
agate kind. 
N . 5 • Pebbles of the blue ground are very differently charged ; 
one of a blue killas is Seeded with innumerable little micaceous 
Spots, of fo faint a caft as Scarce distinguishable from the ground , 
the charge a thin Sprinkling of opake white quartz ; the ftone is 
porous, and to the touch feels rough, as any granite pebble. 
Another of blue killas is charged with pale, flefh-coloured, 
toothy grains, from an inch diameter and under, and differs only 
from the Bofworlas granites (beforementioned page, 10 1) in this, 
that its ground is blue inftead of black. 
Of a blue-black, fome are of a very high poliSh, and clofe 
texture. 
N . 6 . Of the black ground, fome pebbles are So equal a mixture 
of Striated glofly cockle and white quartz, that were not the latter 
in diitinci granules from the fourth of an inch and under, it would 
be difficult to decide which is the ground and which the charge ; 
it is a pretty mottled Stone, but rough and fcabrous to the touch. 
A black flattifh pebble, Smooth, but of no great polifh ; 
its fibres parallel and longitudinal ; it has the properties of a true 
touch-Stone. It was brought me from the fea-fhore in the parifh 
of St. Kevran, and Seems to owe its pebbly figure to the attrition of 
the waters ; fo that it is not unlikely that there Should be there- 
abouts fome courfe of black marble of the nature of the lapis Lydius , 
' 1 ° Oxfordfliire they fometimes fold fuch pebbles wholly pellucid. 
Woodward’s Cat. vol. I. page 32. 
E e 
about the bignefs of a wallnut. 
or 
