326 
there are present a few scattered grains of blue strongly 
pleochroic tourmaline. The albite in this rock is more 
abundant than in the aplite described above. 
e specific gravities of the rocks of this series are 
indicated below :— 
(i.) Fine-grained red aplite, D'8}=2°590. 
(?.) Medium-grained red aplite, D*5— 2:602. 
(?".) Coarse-grained red aplite, D5— 2:605. 
(wv.) Aplite from near Pink Bay, D; — 2625. 
e pink colour of this series is due to the presence of 
a fine film of haematite dusting the cleavages and cracks of 
the alkali felspars. 
IV. PRODUCTS or PxEeUMATOLYSIS OF THE PINK APLITE. 
. These may sted as follows:—(ía) The quartz-tour- 
maline nodules (Pneumatoliths); (5) the greisen; (c) the 
kaolin. . 
quartz-tourmaline nodules have already been 
described in the paper cited above. They were developed 
anteriorly to the greisen, which will now be discusse 
) 
tities of greisen developed as an alteration of the aplite. 
proves to be a greisen, and this grades into an u 
aplite. : 
: In hand specimens the greisen has a porous, fine-grained, 
: light-greenish appearance, and with the aid of a lens qu 
Us ouk and a lightish-green mica are easily recognized. The porous 
~ Character of the rock is well marked. 
