Mineralogy and Geology of a part of Nova Scotia. 327 



They are in the form of the oblique rhombic prism, termina- 

 ted by a rhombic pJane passing from one of the acute solid 

 angles to the other, and almost constantly replaced on the 

 acute solid angles by a single triangular plane resting on 

 the acute lateral edges ; these secondary planes are always 

 small, and never obscure the primary form of the crystal. 

 The cavities, in the laumonite, are often filled with water 

 which serves to prevent the efflorescence of the crystals, 

 which are thus preserved in an unaltered state. The sur- 

 face of this mineral is frequently enriched with crystals of 

 calcareous spar, exhibiting the forms of the rhomboid more 

 obtuse than the primary, and the scalene triangular planed 

 dodecahedron. Large and perfect crystals of apophyllite in 

 the form of the square prism, generally replaced on the sol- 

 id angles by single triangular planes, which are in various 

 degrees of advancement, sometimes almost concealing the 

 primary form are found at this place. This mineral agrees 

 perfectly with specimens in our possession, which were from 

 standard localities in Europe. The crystals are eminently ax- 

 otomous, and this cleavage is so easily obtained, that it is with 

 great difficulty the crystals can be preserved entire. The 

 cleavages parallel to the sides of the right square prism are ea- 

 sily obtained, but the natural joints are not so open as in the 

 direction of the terminal plane. It agrees likewise in chemi- 

 cal characters with the apophyllite from the Bannat ; hence 

 there can be no doubt of its identity with that species. 



This cavern is the first place in Nova Scotia, which fur- 

 nished us with this rare mineral, and as we did not exhaust 

 it, future explorers may obtain a rich reward, for the trouble 

 of searching for this locality. 



We shall next describe French Cross Cove, which is about 

 twelve miles from Peter's Point. At this place, the amyg- 

 daloid and columnar greenstone form together a precipice ri- 

 sing perpendicularly, to the height of three hundred feet, and 

 exceeding in elevation any other we have yet noticed. The 

 entire front of this precipice can be examined only at low 

 water, when it presents four large parallel beds distinctly 

 separated from each other. The lowest is a reddish amyg- 

 daloid, largely impregnated with spheroidal zeolites ; the 

 next is an amygdaloid of the common appearance, and con- 

 tains but few minerals, although it presents many cavities 

 unoccupied. The third layer is rarely vescicular, and seems 

 in fact to pass into amorphous greenstone. The last is com- 



