THE TERRESTRIAL TERIDOTITES. — SAXONITK 127 



has the followiug characters : A yellowish-green groundmass, holding several crystals of 

 eustatite. Under the microscope the section is seen to be formed by a serpentine plexus 

 holding olivine, enstatite, and chromite. The olivine remains only in small grains, sur- 

 rounded by the serpentine, to which tlie remainder of the olivine mass has been changed. 

 The olivine is generally very pure and clear, but its iissures are traversed by the serpen- 

 tine ; grains, even some little distance apart, showing in polarized light that they are por- 

 tions of the same crystal. 



Figure 4, Plate IV., shows the structure of this section. The greenish portion repre- 

 sents the serpentine, the grayish-white portion at the upper part of the section is the 

 partly altered enstatite, the white grains inclosed in the greenish serpentine mass are oli- 

 vine, and the dark grains are chromite. 



Langenberg, Saxong. 



A dull, black, serpentine mass, holding numerous brownish-black bronzite (enstatite) 

 crystals. In the thin section the bronzite crystals show an extraordinarily fine, wavy, 

 fibrous structure, parallel with tlie extinction plane. It contains arranged along the 

 planes of the fibres little opaque needles, and pellicles of hj'drous oxide of iron, and is par- 

 tially altered to a feebly doubly-refracting substance — serpentine. Sometimes the crys- 

 tals are cloudy and altered — bastite. The olivine has been altered to serpentine, having 

 the usual maschcn texture. Magnetite (?), and little crystals of chromite (?) were also 

 observed.* 



CaUcnherg, Saxong. 



This rock has a blackish-green to brown color, and contains little bronzite crystals. 

 In the section the olivine is seen to have been replaced by serpentine, with the usual 

 network structure. The bronzite is also more or less altered, and chromite, hematite, and 

 other iron ores were observed. f 



The Ziegclei, bctivccn Russdorf and Meiisdorf, Saxong. 



A leek-green serpentine, containing bastite (enstatite) crystals. The section shows 

 the mesh structure of serpentine divided from olivine, and fibrous-bastite (enstatite) with 

 chromite and other iron ores. % 



Fatu Lulca and Fahi Tcrmami, Timor. 



Tliis rock, according to Wichmann, is of an oil-green to blackish-green color, and 

 holds bronzite and chromite. Under tlie microscope the serpentine shows the mesh struc- 

 ture, indicating its alteration from oli\'ine. The meshes are light-green to colorless, and 

 the interstitial spaces of a brownish-green color. The bronzite (enstatite) in the section is 

 colorless, and free from all inclusions, excej^t secondaiy products. § 



Rofna, A/j)S. 



A compact, dark, pui-plisli-green rock, containing folia of enstatite, having a jointed, 

 crushed structure, witli the sides coated with greenish serpentine, and presenting a schis- 



* Dathe, Ncucs Jahr. Mill , 1876, pp. 3.38, 339. f Datlie, Neues Jabr. Mia., 1876, pp. 339-341. 



J Duthe, Neues Jalir. Min., 1876, p. 339. 



§ Jaarboek vau Let MijnTezen m Nederlandscli Oost-Indie, 1882, pp. 211-213. 



