UNSTRATIFIED OR IGNEOUS ROCKS 291 
definite shape and are bounded by flat surfaces—that they 
are in fact crystals. Observe, moreover, that the whole 
consists of certain well defined crystalline minerals and a 
mass of matter which appears to fill up the spaces between 
these. This too is crystalline, though the forms of the 
erystals cannot be seen—Granite is a wholly-crystalline 
rock. 
Notice that it does not show cleavage, that it breaks 
with an uneven fracture, and is without taste or odour. 
Determine its specific gravity. 
Test for hardness and note the difficulty with which 
the knife-blade is made to scratch the surface. In this 
connection compare with other rocks. 
Uses. Granite is highly prized for building purposes 
and for monumental work. Its hardness and other 
properties render it capable of taking a high polish, whilst 
the arrangement of its crystalline ingredients gives it, when 
polished, a very beautiful appearance. 
Occurrence. Granite occurs in many countries—the 
Granite of Scotland, where extensive quarries are worked, 
has long been known to fame. It is found also in the 
South Island of New Zealand, in Nelson, Westland, and 
Otago; but so far it has not been met with in situ in the 
North Island. 
Nore.—Although Granite is commonly included amongst 
igneous rocks, there is little doubt that in many cases it has 
resulted from the metamorphism of stratified rocks. An account 
of the considerations which lead to this conclusion cannot be 
attempted here. 
BASALTIC ROCKS. 
Under this head is included a large and important series 
of voleanic rocks which consist essentially of Felspar, 
Augite, Olivine, and Magnetite, with other accessory 
minerals, 
