2.54 Professor Necker on Mineralogy considered 



Scratching apatite ; generally foliated texture. Specific gravity 3.5 to 4* 

 With the blowpipe fusible, with or without intumescence, into glass or enamel. 

 Gen.— Allanite ; Lievrite or Ilvaite. 



Family 8.— Amphiboles. 



Unalterable in acids ; texture distinctly foliated, or fibro-laminary * ; neat 

 and rhomboidal prismatic cleavages ; scratching apatite or fluorspar. Lustre 

 vitreous, passing to the pearly and to the pseudo-metalloid lustre. For the 

 most part fusible alone on the charcoal with the blowpipe. One only is unal- 

 terable viz. anthophyllite. Specific gravity 2.8 to 3.6. 



Gen Epidote (with Zoi'Ate, Withamite, manganesian epidote) ; amphibole 



(with tremolite, actinolite, and hornblende) ; couzeranite ; achmite ; pyroxene 

 (with sahlite or malacolite, diopside, and augite) ; manganese-spaf or rubin- 

 spar ; diallage (schiller-spar, Jameson) ; hyperstene ; anthophyllite. 



Appendix — Schiller-spar of Leonhard; Babingtonite; pyrallolite; triklasite. 

 pykrosmine ; asbest ; Breislakite. 



Family 9. — Wollastonites. 



Soluble in a gelatinous mass in muriatic acid ; distinctly foliated texture ; 

 scratching fluor-spar ; fusible with difficulty on the edges before the blowpipe. 

 Specific gravity 2.8. 



Gen. — Wollastonite or tablespar. 



Family 10. — Disthenes. 



Unalterable in acids; texture foliated ; scratching at most fluor-spar. Before 

 the blowpipe infusible ; becomes white with a fire superior to red heat. Spe- 

 cific gravity 3.5 to 3.6. 



Gen, — Disthene or kyanite. 



Family 11. — Pinites. 



Unalterable in acids ; texture compact or earthy ; scratching only gypsum. 

 Specific gravity 2.7. With the blowpipe more or less easily fused. 

 Gen. — Finite (with Gieseckite). 

 Appendix.— Cry^idXiizedi serpentine. 



Family 12. — Anhydrous Phyllidians. 



IMore oi* less unalterable in acids ; texture eminently foliated, with easily 

 separable and very thin laminae. Hardness difficult to ascertain, on account 

 of the easy cleavage ; some rubbed against glass destroy its polish ; apparent- 

 ly scratch only gypsum. Specific gravity 2.7 to 3. 



Gen All the micas and talcs which do not give out water, nor experience 



any change in their transparency with the blowpipe. Different genera will be 

 found in this family in separating the individuals having a single axis of 

 double refraction, or belonging to the pyramidal or to the rhomboidal sys- 

 tem, or those having two axes, or belonging to the prismatic system. Be- 

 sides these observations, the micas will be distinguished from the talcs by 

 their being flexible and elastic, v^hile the last are flexible without elasticity. 



Appendix. — Rubellan ; perlglimmer ; and pyrodmalite ? 



♦ The fibro-laminary structure so evident and common in all the crystals of this family, shews 

 that all the regular crystals are not simple, but compound individuals, or groups formed of elon- 

 gated simple crystals. 



