92 



University of California Publication's. [Geology 



Since it is so general to think of Naumann's symbols for rhom- 

 bohedrons and scalenohedrons, they are also added in the table. 

 The letters for the forms are those used by Goldschmidt in his 

 Winkeltabellen, and by Palache for the forms on the calcites 

 from Lake Superior. 15 To avoid repetition the average of the 

 measurements with the calculated angles are given in the same 

 table. 



No. 



Letter 



Grdt 



Symbol 





Bra\ ajs 



Naumann 



1 





cc 



10T0 



ccE 



2 



7]- 



10 



1123 



2 p 



3 



0. 



2 



2021 



—2 K 



4 



5. 



i 



1012 



—\ R 



5 





— 11.11 



TT.o.l 1 . 1 



— 11 R 



6 



0. 



— 14-14 



14-0. 14-1 



— 14 R 



7 



P- 



1 



10T1 



R 



8 









2021 



2 R 



9 



t: 



1 I 



2134 



iR 3 



10 



9- 





5279 



|R1 



11 



e: 



1 i 



4156 





12 



B: 



I 1 



17-2-T9-15 



E rl 



13 



C: 



! i 



7186 



R| 



14 



E: 



1 1 



5164 



R § 



15 



F: 



21 



4153 



R| 



16 



K: 



41 



2131 



R :i 



17 



M: 



51 



7-4-TT-3 



R -V- 



18 



O: 



61 



8-5-I3-3 



R -V- 



19 



P: 



71 



3251 



R 5 



20 



U 



62 



10-4-T4-3 



2R| 



21 



X: 



10-3 



16- 7-23.3 



3 R -¥- 





Measured 







Calculated 





No. of 









P 





V 





P 



Meas. 





m n ' 

 uu 



CW1 





30° 



00 



90° 



00 



8 



u 



16 



29 



37 







00 



29 



40 



2 



29 



58 



63 



01 



30 



00 



63 



07 



14 



30 



00 



26 



08 



30 



00 



26 



15 



1 



29 



55 



84 



40 



30 



00 



84 



44 



6 



29 



56 



85 



40 



30 



00 



85 



51 



4 



29 



58 



44 



36 



30 



00 



44 



36 



13 



30 



00 



63 



11 



30 



00 



63 



07 



1 



11 



06 



33 



16 



10 



53 



33 



07 



13 



13 



05 



34 



08 



13 



54 



34 



23 



2 



19 



31 



37 



05 



19 



06 



37 



00 



15 



24 



06 



49 



30 



24 



30 



49 



56 



3 



22 



54 



51 



55 



23 



25 



51 



08 



2 



21 



10 



53 



51 



21 



03 



53 



56 



4 



19 



07 



56 



06 



19 



06 



56 



26 



o 



10 



42 



69 



06 



10 



53 



69 



02 



13 



8 



00 



73 



26 



8 



57 



72 



30 



1 



7 



16 



75 



14 



7 



35 



75 



00 



6 



6 



21 



76 



46 



6 



35 



76 



54 



4 



14 



25 



76 



42 



13 



54 



76 



19 



2 



12 



06 



81 



39 



12 



44 



81 



32 



5 



Prisms. — The only prism present is the unit form, oc R. It 

 is represented by small triangular faces which are perfectly de- 

 veloped and gave very bright signals. 



Pyramids. — On one crystal two bright faces of the second 

 order pyramid f P2 occur. It was not observed on the other 

 seven crystals measured. 



Positive rliomboJiedrons. — The unit rhombohedron -|- R is 

 present on all of the crystals. The faces are narrow but very 

 perfect. They are longer on the crystals of the first generation 

 than on those of the second. Minute faces of a steep rhombode- 

 dron occur on some of the crystals, and one reading showed the 



15 Mich. Geol. Survey, 1898, 6, Part 2, 161-184. 



