[ 452 ] 
Chryftallum difdiaclafticum. JC. 1 
Chryftallus de Rupe. Fahrenheit. 
Chryftai rock. J. C. Boyle III. 229. h. 
D°. a large fhoot. Hauksbee. 
D°. of the rock. Newton. C. Ir. 
Chryftai in the lead-mines near Works- 
worth. Woodward. 
D°. Hauksbee . . 
Do. pure pyramidal, fuppofcd to contain 
Tin. Woodward. . 2, f or 
Chryftallus. Betitus. 
Chryftai. Boyle. , 
Talc, Jamaican. Boyle. * 
Do. Venetian. Boyle . 
d °. j.c. . . : 
D°. Englilh. Woodward. 
D°. a piece like Lapis Amianthus. Boyle. 
A red pafte. J. C. 
A Brasile pebble, foul and feather'd. Hauksb . 
D°. a fragment uncut. Hauksbee. 
D°. cut. Hauksbee. 
Jafper, fpurious. J. C. 
A Cornifti Diamond- cut. Hauksbees 
A Water Topaz, very perfed, but faid not 
to be Oriental. Hauksbee . 
Pebble pellucid. J . C. 
Briftol Stone. Havies. . 1 
Hyacinth, fpurious. J. C. 
Selenites. y. C. . . 
D°. Newton . . * • * 
2.704 
2.669 
2.659 
2.6y8 
2 .6yo 
2.646 
2.400 
2.287 
2.210 
3.000 
2.720 
2.657 
2.600 
2.280 
2.842 
2.676 
.2.591 
2.666 
2.6y8 
2.655 
2.641 
2.640 
2.651 
2.322 
2.2 fZ 
As the mean gravity of Chryftai appears, by the 
foregoing, table, to be little more to that of water 
than 
