106 Minerals from Greenland. [Feh, 



inches by one. The style of the rock in which they occurred 

 must have been on a very magnificent scale. 



Aiigite, 



Although this be a very common mineral, as a constituent lit 

 trap rocks, it was known in a crystallized state only as a volcanic 

 production, until found in the neighbourhood of Arundahl in 

 Norway, In the present collection it occurred abundantly, and 

 in different varieties: first, in slender four-sided prisms, mea- 

 suring 88° and 92°, terminated by dihedral summits, along with 

 crystallized felspar and some light green coloured fiuor, on the 

 surface of a porphyritic greenstone, the base of which is 

 remarkably fine grained : second, in prisms of six sides, being 

 the above form with the obtuse edges replaced by a plane : 

 among these I found one small crystal presenting the primitive 

 form, which is the prism of 88° and 92°, terminated by summits 

 set on the obtuse angle, obliquely to the axis. These are dis- 

 posed on the surface of a granitic rock. Third, imbedded with 

 garnet in granular felspar, as before noticed, and in sodalite 

 blended with amphibole ; also in delicate diverging fibres, 

 formmg stellated groupes of considerable size. In these speci- 

 mens augite eaters into the composition of a rock, which is 

 entirely new to us: its geognostic relation, therefore^ may be 

 looked for with a considerable degree of interest. 



Ep'idote^ 



There were a few specimens which I believe belong to this 

 species ; but without analyses, and in the absence of crystalliza- 

 tion, or soine other prominent character, many of the minerals 

 which present a texture sometimes fibrous and sometimes 

 otherwise, are not very easily discriminated. Those which I 

 consider epidote are massive : one is com.posed of minute 

 interlaced fibres, longitudinally streaked, of a deep clear 

 pistaccio green, and accompanied with felspar and prehnite : 

 another, not so dark in the colour, is almost granular, a few 

 streaked fibres being only to be discovered by means of a lens : 

 the third is a mass of very delicate fibres confusedly disposed, 

 but distinctly visible in the interior of the stone, although the 

 external surface be compact and earthy. This specimen was 

 extremely tough, owing to its fibrous texture. Mr. Jameson 

 observes that massive epidote occurs in beds in primitive 

 mountains : the above specimens have much the appearance of 

 such a locality, except the last, which is more of a kidney 

 shape. 



Prehnite, 



This mineral I found in a rock similar to that of St. Chris- 



