350 Dr.Wackenroder's Mineralogical and Chemical 



consider them to be one and the same mineral, and which, from 

 its peculiar crystallographic characters, he presented as a par- 

 ticular species, of the name of Diopside*, Soon afterwards, 

 however, Haiiy himself published a memoir, in which, after a 

 further investigation of this mineral, he proved, from crystal- 

 lographical reasons, that diopside coincides with pyroxene f. 

 He also found diopside to agree with pyroxene in its physical 

 characters f. 



Having found the specific gravity of themussite to be 3*2374, 

 that of the alalite 3*31, and that of pyroxene from Vesuvius 

 3*3578, he says that the specific gravity of diopside lies within 

 the limits of that of pyroxene, as indeed the remaining external 

 characters of the mineral substances hitherto considered to 

 belong to pyroxene, sometimes differed more from each other 

 than from diopside. , 



Other mineralogists have grouped diopside, according to 

 their different views of the systematic arrangement of mine- 

 rals, with different species, comprehended under augite or py- 

 roxene. Thus Hausmann§ enumerates diopside among the 

 formation of the malacolites in the pentaklasite substance; 

 Leonhard || quotes it as a variety of augite ; Mohs % refers it, 

 together with the coccolite, fassaite, augite, sahlite, baika- 

 lite, malacolite, &c. to the paratomous augite-spar, &c. In- 

 dependent of these well-known classifications of diopside in 

 the different mineralogical systems, it must form, in a system 

 founded on the relation of the external characters to the che- 

 mical composition of the minerals, one of the divisions which, 

 inconsequence of the experiments made on the substituted con- 

 stituents, must now be made in the species of pyroxene and 

 augite. It is in consequence of this that, according to the latest 

 system of Counsellor Hausmann, the diopside is, considered as 

 an augitic substance, and as represented by the formula 



CS 2 + MS 9 . 



To this formation also belongs the diopside which I lately 

 bought of a dealer under the name of Diopside qfFassa, and 

 which I subjected to a strict examination, as we do not possess, 

 to my knowledge, either a chemical analysis or a detailed de- 

 scription of the diopside of the valley of Fassa. 



* Journ. des Mines, torn. xx. 



f u Sur l'Analogie du Diopside avec le Pyroxene;'' in the Ann. du Mus. 

 dllist. Nat. torn. xi. p. 77. Journ. des Mines, torn, xxiii. p. 145. 

 X Journ. des Mines, torn, xxiii. p. 154, 156. 

 § Hanbuch dcr Mineralogie. Band ii. p. 694. 

 || In his Hanbuch der Oryktognosie. New edit. p. 50.3. 

 f In his Grundrus dcr Mineralogie. 2d vol. p. 306. 



I. Miner alo- 



