Prof. Berzelius on two newly discovered Mineral Species. 327 



from the matrix, on account of their great fragility. They do 

 not all of them, possess that dark brownish-black colour, 

 which is generally quoted in the descriptions of Acnnte, but 

 they are sometimes greenish-grey, and of all the intermediate 

 shades between this and the brownish-black colour. In this 

 case, also, their lustre is not so high, and they approach very 

 muc'h in appearance to Mussite, a variety of pyroxene, with 

 which species their regular forms likewise very closely agree. 

 Generally the crystals are macled, and very often bent. 



Art. XXIV. Account of two newly discovered Mineral Spe- 

 cies.* By Professor J. J. Bekzelius. M. D. F.R.S. 

 Lond. and Edin. &c. &c. 



1. Phosphate of Yttria. 



This mineral has been discovered by Mr Tank junior, near 

 I indesnaes, in Norway, in a vein consisting chiefly of a coarse- 

 grained granite. He obtained only one specimen, consisting 

 of an ao-oregate of crystals of half an inch or an inch in diameter, 

 but much engaged among each other. They belong to the pyra- 

 midal system of Molis, and are similar to Fig. 16, Plate Vl-T 

 Cleavage takes place parallel to the faces I, I, in two directions 

 perpendicular to each other, and is easily obtained. The cross 

 fracture is uneven and splintery. Its colour is yellowish- 

 brown, similar to certain varieties of the zircon from Iredcr- 

 ieksvarn ; the streak very pale brown. « Sp. Gr.=4.5577, at 

 a temperature of 16* centigr. Hardness =4.5 . . . 5.0, between 

 floor and apatite, nearer the latter." It possesses resinous 

 lustre, the higher degrees of it upon the faces of cleavage, the 

 surface of the crystals being nearly dull, and faintly transit- 



cent. ,11 v 



Before the blow-pipe, it resembles very much phosphate oi 



• Extracted from Kavgl V<t*n*kap» Acad. Uandlmgav for I8»^p. 38*. 

 aud PoKEeudorfs Annalen der Physik. 18fc5, ii, ?• 803. 



\ Thf figures of these crystals, and that oi' the cry, Id - of Polym.g.ute 

 we« observed by Mr Haidinger, on specimens in the possesion oi Mi 

 Tank- 



