378 COMPACT FELSPAR. 



SECOND DIVISION. 

 Compound. 



a. Containing dispersed particles of horn- 



blende, insufficient in quantity to 

 alter its character. 



b. Containing interspersed particles of 



quartz. 



These pass into those varieties of gneiss with 

 which they seem to be invariably associated, and 

 are, of course, not always definite. 



The colours of compact felspar are various. 

 I have observed it white, ash-coloured, smoke 

 grey, dark grey, greenish grey, reddish brown, 

 black, olive green, and bright yellowish, or grass, 

 green. Several colours are also often intermixed, 

 and it is not unusual for a mass of one colour to 

 be intersected by filamentary veins, or very thin 

 flat, or laminar, veins of another. 



The simple varieties also, pass into the gneiss 

 with which they occur. 



I know not that it ever contains any imbedded 

 minerals except those above-mentioned. 



