64 



On a Meteoric Stone found in New Zealand. 



clear, isotropic glass and granularly devitrified anisotropic glass, and is 

 full of minute, dark grains, probably of iron ore. The portion below 

 the dotted part, near the edge of the figure, is mostly true glass and free 

 from oxide of iron, but encloses a few small grains of olivine. The 

 remainder of the section is occupied by finely and coarsely granulated 

 olivine, strongly stained in places by brown hydrous ferric oxide, and 

 there are also scattered dark grains — some rather large — in one of 

 which, on the left of the centre of the figure, reflected light reveals 

 numerous fine silvery- white metallic specks of nickel- iron. This is 

 the only direct evidence of the presence of this metal in the section, 

 but it is very probable that amongst the other large dark grains one 

 or more consist of it to some extent, being rendered dull non- 

 metallic-looking by oxidation. 



Fig. 6. — This is drawn under twice the magnifying power used 

 for the other figures, in order to show more clearly an occurrence of 

 intermingled isotropic and devitrified anisotropic glass. The mass 

 extends from the lower margin of the figure between a particle of 

 nickel-iron on the right and an olivine chondrule on the left, upwards 

 through the centre to the large particle of nickel- iron at the upper 

 margin, being wider both at the top and bottom than in the centre. 

 It is crowded with small, yet well-defined, grains of olivine, but 



Fig. 6. 



adjoining the lower particle of nickel-iron, and near the upper one, 

 there are irregularly outlined portions quite free, or nearly free, from 

 these grains, in which the true glass can plainly be distinguished 

 from the granularly devitrified material between crossed nicols, on 

 rotation of the stage of the microscope. Besides this mass of glassy 

 substance, the particles of nickel-iron, and a few black grains, only 

 olivine is represented in the section ; the fine granular chondrule on 

 the left having for the greater part a rim of larger grains, the 

 divisional joints of which stand closely radial. 



