'' CORINDON FOUND IN ITALY. 103 



VIII. 



Letter from Profcffor Pini, lnJ])eaor of Mines to the llaUm 

 Republic, to J. C. Delametherie, on Carindon found in 

 J tall/ * 



1 HE intereft you take In publiftiing difcoveries in natural Beautiful reJ 



x-a • II T 1-7 . •„- adamantine fpar 



hiitory ni your excellent Journal, niduces me to communicate ^^^^^ .^ j^,^^ 

 to you a niineralogical rarity lately fbuncl on a mountain of the 

 Italian republic: it is a very fine corindon, or adamantine 

 ipar, of a deep ruby colour. I law it for the firlt time among 

 tiie minerals which the learned Brochi, profetfor of natural 

 hifiory at Brefcia, had made a (hort time before in the depart- 

 ment of Serio. At the firft view he conlidered it as a feld- 

 fpar, of which it has all the appearance; and, in fa<f^^ the 

 corindon being a fubt^ance which hitherto has only been fur- 

 Tiiflied by countries far diftant from us, it would have been 

 imprudent to have judged otherwife at firft : but the colour of 

 Hone, exa^Iy refembllng (hat of a red corindon which I 

 brought from Paris, given to me as coming irom Madras, 

 led me to fuppofe th.^t it did not difier from it. 



But as ProfelTor Brochi purpofed meeting me in a fliort 

 time at Milan, to which place I was going, we poilponed the 

 verification of this fufpicion. When he law the red corindon 

 from Madras, in my polfeffion, he no longer doubled the 

 identity of its fpecies with that of our fample. I afterwards 

 difcovered the fame identity in the trials to which I iubmitted 

 it : the following are the refull^ : 



1ft. The corindon of Italy fcratches the hardefl rock-cry fial. Examination. 

 2d. It does not melt before the blow-pipe, either alone or with '■ ^^/'l"^.^!* 



, ,. . „ , " , • . , . , . , r I 2. Infufibility. 



the addition of borax. 3. Us texture is in laminae, which tal- j. Laminar tex- 



low different diredions. 4th. Its filTure is triple, and when tuic 4. FilTure 



it is cut in the three diredions, it offers a rhomboid, the acute r. Rgfledion of 



angle of which is 6'1|®. 3th. Its crofs fradur^ fiiews the light. 6. Sp. 



fplendor of the diamond, and refleds the light, the flaflres of ^'^^^^^^^ 



which are almoft the colour of filver, 6th. Its fpecific gravity 



is 3.87, which is the mean of that of the true corindon. 



Hitherto it has been met with in a mountain of micaceous Is found on a 



fchiftus, in pieces of feveral inches in length, which are amor- "mountain of mi- 

 ' * to ' caceous fchiftus. 



* From Journal dq Phyfique, Vendemiaire, An XIII. 



phous 



