, C 430 ] 
occidental, from Spain , Germany , Bohemia , Silejtd. 9 
&c. ; that in Perjia , where it is found in greateft 
Plenty, it adheres to black Stones, as if it were an 
Excrement or a Tranfudation from them. A Stone 
of this fort is feldom found to exceed a Walnut in 
Size $ and he mentions one in the Great Dukes 
Mufeutfi , on which the Head of Julius Ctefar is en- 
graved, as a very extraordinary Sample : He adds; 
That he never faw one bigger than an Hazel-nut; 
that fome of the oriental ones have the Faculty of 
preferring their Colour perpetually, which are called 
Stones of the old Rock ; and that others lofe their 
Colour gradually, and are called of the new Rock. 
He then gives an Inftance of a Turquoife which had 
loft its Colour upon being laid by fome time after 
its Owners Death, which recover'd its beautiful 
Colour upon our Author's wearing it upon his Fin- 
ger in a Bang. 
Ctejius , in his Treatife de Miner alibus, p. 601. 
fays, This Stone is called Turcots by My Hus 7 in his 
Bafilica chemica ; by Albertus Magnus , in his 
Treatife of Minerals; and by Rueius > in his Treatife 
of Gems : but Turca , by CauJJtfius de Lapillis Jym - 
bolicis, P)e Boodt , and Dr. IVoodwardy * with other 
modern Writers, take it for the Callats of Pliny . 
Salmajius, . in his PI ini an. Exercit. p. 142. fays. 
Many have miftaken the modern Turquoife for the 
Cyanus , but that the Cyanus was tranfparent like 
the Saphire ; whereas the Turquoife is a fort of Jafper. 
Dr. IVoodwardy in his Letter to Sir Jo. Hoskyns , f 
fays, That the Turcois y or Calldis of Bliny> is no- 
thing clfe but foflli Ivory tinged with Copper. I 
do 
* Method 0 1 Fcjffils, Letters, p. 17* 
f Ibid . p. 16. 
