A SYSTEM OF 
contributed not only to the fluors being reckoned 
of the fairie value as the coloured quartz cryftals, 
by fuch colleftors as only mind colour arid figure •, 
but alfo to their obtaining a rank among the pre- 
cious ftones in the apothecaries and druggifts 
Ihops. They, however, may be permitted to 
onjoy that honour, fince our modern phyficians 
do not make piore ufe of them than .of the 
others, 
SECT. CIL 
The Seventh Order,' 
The Albeftus Kind, AJbeJlin^. 
Thefe are only yet difcovered in an 
indurated ftate : their charadlers are as fol- 
low, 
1. When pure, they are very refraftory in 
the fire. 
2. In large pieces they are flexible; 
3. They have dull or uneven furfaces. 
4. In the fire they become more brittle. 
5. They do not ftrike fire with the fleeL 
d. They are not attacked by acids. 
7. They are eafily brought into fufion by 
borax. 
In this order are included both thofe 
varieties which by foflTilogifts have been 
^ mentioned under the names of Amianti 
and AJheJii^ and have often been con^ 
founded together, 
SECT, 
