

RON A. MINERALS. 215 



cretions, which are always connected with the graphic 

 mixture of quartz and felspar before mentioned. It 

 is of a brownish-red colour and glassy lustre, and is 

 intersected by opaque threads ; a circumstance common 

 in this variety of felspar. 



The quartz, independently of the aspect above men- 

 tioned, is often also remarkable for a green colour, 

 which is generally dull, and appears to arise from fibres 

 and laminae of the green felspar. It occasionally also 

 contains mica, as well as hornblende ; while, being 

 of a nearly crystalline transparency, it transmits their 

 colours, acquiring thus a fallacious hue of green or 

 black. In similar circumstances it often appears of a 

 brick red from an intimate mixture of felspar. Coloured 

 quartz of the usual character is also found in different 

 places, and most abundantly on the skirts of the hills 

 near Archasig vore. It varies from pink to dark reddish 

 purple, the latter adding a variety of no very common 

 occurrence to those already described on former occasions. 



In the natural cavities of the hornblende schist that 

 mineral is sometimes found crystallized, but in the 

 specimens which I procured the prisms were without 

 regular summits. 



I have only to add that tetraedral grouped crystals 

 of oxidulous iron are not unfrequent in the granite veins. 



