814 Mineralogy and Geology of apart of Nova Scotia, 



tabular masses, which are evidently the ruins of veins from 

 the overhanging trap rocks. The specimens of this vicinity 

 frequently contain the outlines of many fortifications in the 

 compass of a few inches. The base of this agate is an 

 opaque white chalcedony, alternating with rows of transpa- 

 rent quartz and yellow jusper, the last generally constituting 

 the external layer. 



Brecciated agate, composed of angular and spheroidal 

 masses of red and yellow jasper, of fine texture, cemented 

 by transparent and amethystine quartz, often enclosing in 

 geodes, beautiful crystals of purple amethyst, which, cover- 

 ing the whole interior of the cavity with protruding crystals, 

 vie in beauty with any specimens brought from the banks of 

 the Rhine. A large geode was found near the estate of 

 Mr. Titus, on the shore of St. Mary's Bay, which, weighing 

 more than forty pounds, was composed almost entirely of 

 the richest purple amethyst, the mass having but a thin coat 

 of fortification agate externally. On examination of the 

 crystals of this geode, we found a substance of a reddish 

 brown color, traversing the amethyst, in fibres, or acicular 

 crystals, which, beginning at the implanted extremity of the 

 crystal, shoot out into diverging scopiform and fasciculated 

 groups, to the opposite extremity. On exposure to a full red 

 heat, this amethyst loses its color, becomes transparent, and 

 has a vitreous lustre ; the included fibres, at the same time, 

 are changed in color to a dark brownish black. On fracture 

 of one of the crystals of amethyst, we obtained a portion of 

 the fibres, which on examination before the microscope, 

 showed a reddish brown substance, with specks of a brass 

 yellow, which we recognized as sulphuret of iron, the color 

 being very speedily changed to brownish black by exposure 

 before the blowpipe, when it became magnetic, as did the 

 surrounding brown substance. We are then led to conclude 

 that the yellow was iron pyrites, and the brown fibres red 

 oxide of iron, which doubtless, had its origin from the decom- 

 position of the former. The amethyst, traversed by this sub- 

 stance, was of a much deeper color than that in which it was 

 not present, and the color appeared in the immediate vicin- 

 ity of the fibres ; hence we should be led to think that a 

 portion of its color was derived from this mineral. The 

 fibres are so minute, that we are unable to ascertain if 

 manganese be present in them. 



Large masses of red jasper, weighing more than a ton 

 each, lie scattered along the base of Titus 1 Hill, which rises 



