On Cordierite as Contact Mineral 



by 



Yasushi Kikuchi. 

 Witli Plate XXVIII. 



The occurrence of ( îordierite in some metamorphosed rocks along 

 the margin of the granitic intrusion has often been recognized in many 

 places in Europe. In this condition, however, the mineral seems to 

 be only of secondary prominence, being usually found as formless 

 grains associated with other minerals of contact origin, such as 

 Andalusite, &c. The case which we have to describe is of especial 

 interest, since so far as we know, ii is an instance in which this 

 mineral has been solely developed as :i result of contaci metamorphism 

 in a very peculiar modification, differing from the ordinary form of 

 Cordierite by want of pleochroism, and the structural habit of its 

 crystal which is hitherto unknown. 



The volcanic product of Asama-yama has yielded an interesting 

 ( îordierite- rock, which was microscopically studied by Dr. E. Hussak.* 

 This Cordierite, the characters of which I was also able to examine 

 myself by the specimens kindly furnished to me by Dr. T. Harada, 

 differs from that here to he described, as might have been expected 

 from the different mode of its origin. 



* Ueber dea Cordierit in vulkanischen Auswürflingen — Sitzungsb. cl. k. k. Akatl. d. Wiss. 

 in Wien. Mathem.-Naturwiss. Classe. 1883, Bd. LXXXVII. p. 332. 



