LIME. 



225 



succeeding years. It was observed that galena almost always occurred in veins of this spar ; 

 and as these veins were very abundant, they were frequently opened at considerable expense, 

 when there was not the least appearance of ore to warrant the outlay. It will be unnecessary 

 for me therefore to notice in detail all the localities of calcareous spar in this county, as it 

 occurs in some form or other at all the so called lead " diggings." 



Tlie finest crystals have heretofore been found at the Rossie lead mine. Their forms are 

 exceedingly various, and require particular descriptions. Crystals of a delicate straw-yellow 

 colour, almost perfectly transparent, and from eight to ten inches in diameter, have occa- 

 sionally been found in this vein ; while smaller ones, variously aggregated, have been obtained 

 from it in vast quantities. They occur in the water-filled cavities of the mine, and are asso- 

 ciated with crystallized galena, iron and copper pyrites, and rarely crystallized celestine. 



In addition to the primary form, which is common, we have here the primary with two of 

 the solid angles replaced by tangent planes. Fig. 91, P on c 135° 0'. These planes are 



Fig. 91. 



Fig. 92. 



Fig. 93. 



variously extended. Twins, as I suppose, of the above form, are also found. The face of 

 composition is at right angles to the vertical axis, and the crystal has a triangular outline. 

 Fig. 92. In other cases the face of composition projects, as in Fig. 93. Another twin, which 



Fig. 95. is common here, is that 



which is represented in Fig. 

 94. All these forms are va- 

 riously modified. The dis- 

 torted scalene dodecahedron. 

 Fig. 95, credited to Rossie, 

 is from Dana's Mineralogy. 



It is proper to state, that 

 the crystals from which se- 

 veral of the above figures 

 were drawn, were obligingly 

 loaned to me by Dr. Em- 

 mons, whose collection of minerals from this county is unrivalled for extent and beauty. 



Near De Long's mill two miles from the Rossie mine, at the Jepson vein in Rossie, at the 

 Wilson vein in Gouverneur, and at Mineral point on Black lake, specimens have been found 

 similar to those already described, but they seldom exhibit such a variety of forms. 

 MiN. — PartII. 29 



