476 ON THE NEWEST FLOETZ-TRAF 



lish, the colours are neither various nor beauti- 

 ful. 



QUARTZ. 



Independent of the transition of jasper into this 

 species, I have found small veins of white or grey- 

 ish-white quartz traversing the trap-formation in 

 every part of the county. Where it has room 

 to expand into crystals, as in drusy cavities, it 

 assumes the usual form ; and I have observed in 

 some places very regular dodecahedrons, or double 

 six-sided pyramids, adhering to the walls of the 

 cavity by one of the apices. 



HEAVY-SPAR. 



Some veins of this mineral occur at the Garl r 

 tofts ; they are of the foliated variety, yellowish 

 and brownish- white, and a few inches in thick- 

 ness ; they intersect the same beds as the veins of 

 jasper, and run very nearly in the same direction. 

 The veins I have found at Pencraik, and in other 

 places, are not half an inch wide. 



