Chap. IV. 2.] metamorphic rocks. 93 



Associated witli the mag-nesite are minute veins of Baltimorite, or 

 Associated minerals ; Abrous serpentine, generally of pale g-reen colour, 

 but here and there the largest of these veins (never 

 exceeding- G inches in thickness) show pieces of a rich hlueish-green. The 

 weathered and water-worn rounded fragments to be picked up in the 

 nullahs draining the northern area, not unfrequently show rich tints of 

 yellow, brown, red, and purple, but on the outside merely, proving these 

 colours to be due to weathering only. 



Of compact serpentine, only very small fragments were found in one 

 or two nullahs, as pebbles. 



Thin coatings of calcedony not unfrequently cover the surface of 



the magnesite, or penetrate into the mass of it ; the 

 Calcedony and jasper. ■ in • o 



calcedony itselt is frequently covered with a layer 



of very minute crystals of quartz. The calcedony appears also in the 



earthy mass which the magnesite veins traverse, especially in the northern 



area and at the south-east extremity of the south ridge, and in this 



reddish or brownish earthy rock, it occurs so frequently as to cause portions 



to pass into impure jasper, numerous fragments of which, of reddish 



colour, may be seen strewing the ground, more especially where the 



magnesite veins are least numerous, e. g.^ at the east end of the south 



area, where the matrix rock presents to a very remarkable degree the 



appearance of having been baked and burnt into a cindery consistence. 



Here the calcedonic and jaspery coating and net-work of in- 

 numerable small threads and veins penetrate the rock in every direction. 

 The magnesite also not unfrequently forms such a net- work in the imme- 

 diately surrounding rock. 



The rarest of the minerals associated with the magnesite, and the 



only one of any practical value, is chromate of iron, 

 Chromate of iron. r« i • i 



fragments oi which occur here and there. An im- 

 portant vein of this valuable ore was discovered many years ago near 

 the ceutie of the northern area, and was worked by the Company formed 



(315) 



