122 ^ N A T U R A L ; ILLS t 'lQ R Y
A E has this farther peculiarity that its] (hoots tend all one waj^
whereas, mother cryftal; lump?,' they, point tliiferently^ccQDdmg
to ‘the^be^ • «be® '“ fe $ *** pM “8 M g Lhave yet
feen -It-came from Trevafeus mine, in-tHe pariffi .ofGwymer. ;
Lief xxix.' is aft afterifk of the eleareft :cryftaU its. rays. hexagonal
Swelling or gibbous in the huddle; their fides not redilineaiy
but ridged near the edges, and fomewhat holldwi hut rifot uniformly
fa, betwixt the ridges,; T h e extremities are entire, : ending in one
fbarp point; and it is-yeiy plain that theyneverhadany pyramidal
apices: the rays near the bafe fpread horizontally, but-the others
raife themfelves, gradually making.* *.greater.angle tih the^middle
and higheft make nearly a right angle with the bafe. I have teen
one more of this kind^ but not fo entire as this curious fpecimen .
Fig. xxxiv. a triangular pyramid, the fides confining of mangles
equal to one another, and to the bafe. gj
Fig. xxxv. a triangular cunoeid jointed cryftalf the .bale or' the
one alternately contiguous to the apex of the next ^ jo in iA .r . ?
Thefe are the principal varieties o f cryftal which a eoileton ot
fome years from our Cornilh mines has afferded, and I doubt- not-
but new diftindtions and different forms, and very likely mor&elegant
fpecimens, will occur to gentlemen who will induftrioufly^lfg,'
compare, and fet in'order, the cryftals of different mines.' O f this,
the curious Mrs. Grace Pereival ofPendarves (to whom thisxolleamn
is indebted in more than cine mftance) hasofferedus a- fair ^pattern,
by fixing fide by fide in herFoflillary an infinite number bf.fcryttals
of various and the eleareft waters, in all fhapes, firigle and in duffers;
moftly out of mines in her own lands, all QUt of ber neighbout-
hood. So many rich fubjeds will well remunerate the attentive
infpedion of every inquifitive Foffilift at hfer feat of Pendafves, in
the Parffh of Gambom, Plate the XIV.
s e c t . v. The figures in Plate XIII. are all of the natural frze, but the
Theirfize. bodies defcribed are not alwayi o f the largeft kind. The' largeft
hexagonal eiyftal which I have yet feen found in Cornwall, is ten
inches and a half in girt near the bafe, and feven inches and three eighths
high. It weighs three pounds and half air ounce. From this fize we
have thefe* cryftals of all dimenfions down to that of a fmall pin.
s e c t . vi. They are fometimes of a fine clear water, and are therefore
Tranfparen- rrtmmonly railed Cornifli diamonds, and of all our baftard diamonds
cy znd colour ^ this nation efteemed the beftp; but they are hot all coldurlefs,
* The intermediate numbers are explained in the Corhiifi are the. heft, much better than thofe
the following pages. .
p « Of our baftard diamonds here in England ’ R. S.- Part 111. Wnap. iv*
feme