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between the Liparefe and Etnean chryfo- 

 lites will be feen by comparing the defcrip- 

 tion I have given of the former with what 

 M. Dolomieu fays of the latter, in the work 

 I have frequently cited. He tells us, that 

 fome of the chryfolites he found there are 

 amorphous, others cryftallized in tetra- 

 gonal or hexagonal prifms, fometimes with 

 an hexagonal pyramid ; that their fracture 

 is partly concholdal, and partly lamellar; 

 that they are harder than quartz ; that they 

 are more or lefs tranfparent ; that their co- 

 lour is a greenifli yellow, with various 

 tinges, and that they are fufible in a ftrong 

 fire. He does not give their fize, but they 

 cannot be large ; both becaufe he calls them 

 grains^ and becaufe thofe which I obferved 

 in fome lavas of Etna were very minute. 



I have defignedly called the chryfolites of 

 Lipari, volcajiic chryfolites, not merely be- 

 caufe they are found within a lava, but to 

 preferve a diftindion between them and the 

 gem of that name ; fmce I know that fome 

 refpedable authors are of opinion, that the 

 D 4 volcanic 



