lis A SYSTEM OF 



contributed not only to the fluors being reckoned 

 of the fame value as the coloured quartz cryftals, 

 by fuch collectors as only mind colour and figure •, 

 but alfo to their obtaining a rank among the pre- 

 cious Hones in the apothecaries and druggifts 

 fhops. They, however, may be permitted to 

 enjoy that honour, fince our modern phyficians 

 do not make more ufe of them than oJ the 

 Others, 



SECT. CII. 



The Seventh Order. 



TJie Afbeftus Kind, AJbeJlin*?. 



Thele are only yet difcovered in an 

 indurated Hate : their characters are as fol- 

 low. 



j. When pure, they are very refractory 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 fteel, 



6. 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 fofiilogifls have been 

 mentioned under the names of Amianti 

 and AJbefiU and have often been con? 

 founded together. 



SECT- 



