NOTES ON THE MINEKALS OF JAPAN. 273 



MoRAiYAMA in Shinano. — Iwasaki lias described a number 

 of partly decomposed potash felspar crystals from Moraiyama, 

 collected by Okubo together with smoky quartz in a pegmatite. 

 They are 2 to 4 cm. in length, and usually covered with brown- 

 ish decomposition product. Observed crystal faces are c/=Pœ, 

 oP, CO p^ CO Pa^ P, Pcö and ^Pôô. Simple crystals are rare; 

 the specimens are usually in Baveno twins. The same twinning 

 is sometimes repeated, thus producing twins of three or four in- 

 viduals. Sometimes two Baveno twins are united, leaving a re- 

 entrant angle at their union ; and even four of them may unite 

 causing a central depression on one end of the composite crystal. 

 Albite lamellae are enclosed in the crystals, but they are not 

 visible with the naked eye, unlike some of the Omi and Mino 

 specimens. 



118. Albite. 



Wada possesses a good specimen of albite druse found in Tosa 

 Province. The white spots and grains in the chlorite-amphi- 

 bolite of KwANTô are believed to be albite. Besides we have 

 in the pegmatite of Omi and Mino, albite as crusts and lamellae 

 in potash felspars, and as minute crystal-aggregates. 



119. Andesine. 



Shioda in Shinano. — Swiall crystals of this mineral, about 

 0.6 cm. long along the ä axis, are found as porphyritic crystals 

 in a compact grey plagioclase-rhyolite, which is almost entirely 

 decomposed in yellowish-grey easily crumbling masses. Crystal 

 faces are co p ^^ oP, ,P, c^, a)'P, coP'^ od'P« , and ^ F'n . There are 

 found rectangular, cross shaped, or broad tabular roundish forms 

 of individuals. The last two forms are Carlsbad twins consisting 



