Mineralogy and Geology of a "part of Nova Scotia. 1 4 1 



rocks at this place, and then describe the minerals before al- 

 luded to as occurring in them. The shore is fronted by a 

 steep bank of about one hundred feet high, from the base of 

 which a slope of debris, detached by the frost, inclines down 

 into the sea. One half of this bank consists of trap and the 

 other of red sandstone, intermixed with red shale. Upon it 

 rests a ridge of columnar greenstone. These two rocks come 

 boldly into contact with each other, and the sandstone and 

 shale dipping beneath it, at an angle of forty degrees has the 

 breccia and amygdaloid recumbent on, or more properly, in- 

 clining against it ; thus presenting, when viewed from the 

 sea, a section of the two rocks crowned with the columnar 

 trap. The amygdaloid is vesicular, and furnishes most of the 

 minerals which we are now to describe. They are chaba- 

 sie, analcime, heulandite, calcareous spar, and siliceous 

 sinter, all of which occur abundantly, and are often seen 

 richly congregated in the same specimen, or included in the 

 same cavity of the rock. 



The chabasie, grouped with its associated minerals, is usu- 

 ally of a wine yellow or flesh red color; but in a few instan- 

 ces it is nearly colorless and transparent. The crystals, which 

 are frequently three fourths of an inch in diameter, exhibit 

 the form of the primary obtuse rhomboid, sometimes so mod- 

 ified, as to assume the lenticular hemitropic form represented 

 in Phillips' Mineralogy, p. 1 38. At other times, from the 

 almost innumerable faces of composition, they become inde- 

 scribably complex, or at least would require, for a precise cry- 

 tallographic description, the consummate skill of a Haiiy, 

 a Mohs, or a Brooke. They are slightly striated, of a glisten- 

 ing vitreous lustre, and often hemitropically united. This 

 chabasie agrees in all characters excepting color and com- 

 plexity of modification with that from the Scottish Islands. 



The analcime is in white opaque crystals, exhibiting the 

 passage of the primary cube into the trapesohedron, which it 

 frequently completes, and thus forms crystals which, having 

 twenty four equal and similar trapeziums, entirely obscure 

 the primary planes. 



Over the analcime, the heulandite is thickly implanted in 

 small, but extremely brilliant pearly white crystals, which are 

 transparent or translucent, and usually in the primary form, 

 sometimes slightly modified. 



The calcareous spar is crystallized in very acute rhom- 

 boids, of which scarcely two can be found possessing similar 



