a New Mineral Species. 277 



from Fergusonite, and: which Mr NORDENSKIOLD ascertained to 

 be an yttro-tantalite. This substance is crystallised in regular 

 octahedrons, the largest of them half a line in diameter, present- 

 ing no cleavage, but rather perfect conchoidal fracture. Its 

 lustre is resinous, almost imperfect metallic, at least in the frac- 

 ture ; for the surface of the crystals, though very even, possesses 

 but little lustre, the colour is pale yellowish-brown, the streak 

 still lighter, almost of the same colour as that of Fergusonite, 

 and it is translucent on the edges. It is brittle, but the hard- 

 ness inferior to that of Fergusonite, being only between 4.5 and 

 5.0. 



The locality of this species is Godhavn in Greenland, where 

 it is found imbedded in Albite, with cleavable octahedral Iron-ore 

 and Fluor. It resembles the yellow Yttro-tantalite of BERZE- 

 LIUS ; but the forms of this substance not being known, it is as 

 impossible to say whether they belong to one species, as it is 

 with other varieties of Yttro-tantalites and the Fergusonite. 



Several of the properties of Fergusonite have been quoted by 

 Mr PHILLIPS among the characters of Yttro-columbite, and some- 

 thing analogous to its form is represented as a crystal of Allanite. 

 The chief difference of this figure from the real crystals of Fer- 

 gusonite is, that the faces *, which appear on their extremities, 

 are inclined either to the right or to the left of each face of the 

 four-sided prism, while in the figure quoted above, they are re- 

 placed by an eight-sided pyramid, appearing with the full num- 

 ber of its faces. 



The mineral from Bastnaes, called Cerite by HISINGER and 

 BERZELIUS, possesses many properties in common with Allanite. 

 On account of its agreement in regard to chemical composition, 

 it has been supposed by many mineralogists to constitute with 

 it but one and the same species. It would be too precipitate to 

 form at present a decided opinion on this question, as long as the 



