-4] Murgoci. — Classification of the Amphiboles. 



TiO. from the Ti-bearing amphiboles during the transformation 

 of the eruptive rock in a crystal line schist,* 



The crocidolite was described above (Part I). The relations 

 with katophorite are the same as in the rocks of Rosita Hills, 

 etc. The angle of extinction of crocidolite (ft:c) is opposite to 

 that of katophorite. 



Another specimen of the same syenite of Spanish Peak shows 

 no katorphorite nor crocidolite ; the structure is hypidiomorphic. 

 The amphibole is here a soretite; it occurs as long prisms with 

 (110) and (100) more developed than (010), with many inclu- 

 sions of albite (and magnetite) in a poikilitic structure. Pleo- 

 chroism: C = greenish blue, t) = olive-green, a = honey-yellow. 

 C<b>a. Angle of extinction -24° (t:c); axial plane 

 parallel to (010). y — /3 = 0.012 ca. 7 — a = 0.024 ca. 2 V 

 very large, negative. Apatite, chlorite, albite. 



Quartz diorite. -]■ m. from Flume, Oak Ridge (5 m. east of 

 Calaveras Valley). IV. 1. 



Ilmenite, hematite, titanite as large reddish yellow, crystals, 

 chlorite, biotite, acid oligoclase with crystals of lawsonite, pegma- 

 titic and granophyric quartz. 



Katophorite : C = reddish brown (if altered: greenish or 

 bluish) ; 6 = olive brown, d = light yellow. C ^ J) > 9. The 

 colors not uniform, with dirty patches and zones; ext. -26°; 

 hemitropic lamellae; axial plane parallel to (010) ; negative. 



The katophorite passes over into fibrous crossite (?) at the 

 periphery, as the katophorite from Spanish Peak does into croci- 

 dolite. 



Ferruginous biotite as pseudomorphs of hornblende with zones 

 of leucoxene or rutile, chlorite, and a bluish aetinolite result also 

 as a secondary product of katophorite. 



CONCLUSIONS. 



From this short description of some of the most interesting- 

 rocks of California we may conclude : 



I. The glaucophane schists are in general crystalloblastic 



rocks :f lawsonite, epidote, zoisite, sometimes titanite, ilmenite, 



* F. Beeke. tiber Mineralbestand und Structur der Krist, Schiefer. C. B. 

 IX. Congres de Geologie, Vienne 1904. 



f The nomenclature proposed by F. Beeke, loc. tit. 



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