146 PERIDOTITE. 



A. E. 207, four miles northwest of Eanedeli, is a compact greenish-brown rock, weath- 

 ering rusty-brown, and contains enstatite crystals. Section : greenish-gray and composed 

 principally of secondary serpentine, with its network structure holding later altered oli- 

 vine grains, and altered enstatite crystals containing much iron ore, and traversed and 

 stained by ferruginous material. Many of the olivine grains between the meshes appear 

 in common liglit as unchanged olivine, but in polarized light the change to serpentine is 

 seen to be complete. Some dolomite occurs, while portions of the section present a 

 similar structure to that given in iigure 4, I'late VI. 



A. E. 482, from the central part of the Chiplak, j\It. Ida, is a greenish-gray schistose 

 rock closely resembling some mica schists owing to its contained talc scales. It holds 

 actinolite and yellowish-brown altered olivine. Section • greenish-gray and composed of 

 olivine, iron ore, secondary serpentine, talc, and actinolite. I am inclined to regard this 

 rock as an altered massive rock, instead of a metamorphosed sedimentary one. 



A. E. 265, from the summit of Mt. Ida, is a similar schistose rock, composed of 

 olivine and actinolite, with talc scales lying between the lamination planes. The section 

 is composed partially of olivine, which is somewhat altered to a dirty-green serpen- 

 tine, and partially of actinolite crystals. Iron ore and talc also occur. Mr, Diller 

 has called this a talc schist ; but I am unable to agree with him, for it appears to 

 me to be a metamorphosed peritlotite, in which the actinolite and talc are alteration- 

 products. The foliation appears to me to have been produced during the metamorpliosis, 

 and not to be congenital. 



A. E. 485, from the northwest summit of Mt. Ida, is a schistose rock of a grayisli- 

 green color. The schistose structure appears to be due to alteration and to the production 

 of talc scales. Section: composed of a network of greenish serpentine containing olivine 

 and secondary actinolite and talc. The form of the olivine grains, and their relation to one 

 another and to the other minerals, are such that I am unable to look upon them as eitlier 

 of mechanical or of metamorphic origin. The actinolite is clearly an alteration-product, 

 and frequently separates portions of tlie same olivine individual. 



There are two rocks numbered A. E. 483. One, coming from the central part of the 

 Chiplak, Mt. Ida, is a compact greenish-black rock containing talc scales and weathered 

 brown. The section is composed of serpentine, olivine, actinolite, talc, and iron ore. 

 The alteration of the olivine has been quite extended in this. The second A E. 483 is 

 from the northwest summit of Mt. Ida, and is a darlc compact rock with little trace of a 

 schistose structure. The section is composed chiefly of serpentine, talc, iron ore, actino- 

 lite, and a little olivine. 



A. E. 473, from the summit of a ridge east of Mt. Ida, is a dark greenish and grayish 

 rock weathering brown. It is a surface specimen. Section composed of a network of green- 

 ish serpentine holding olivine grains, and associated with actinolite, talc, iron ore, etc. 



A. E. 217, from the Kemar Valley, is a compact dark grayish-green rock with green- 

 ish and grayish porphyritically enclosed enstatite crystals. Tlie section is composed 

 principally of a clear pale greenisli and yellowish serpentine, holding diallage, enstatite, 

 some talc, and iron ore. The serpentine shows traces of the structure of the minerals 

 from which it was formed. 



A. E. 216, from the same valley, is a similar rock, and in the hand specimen pre- 

 sents considerable resemblance to that described from High Bridge, N. J. The section 

 is mucli like that of A. E. 217. The altered enstatite and diallage have ferruginous 

 material so arranged in their fissures as to give them a close resemblance to bronzite and 

 hypersthene. 



