428 Whitlock—Calcitefrom West Paterson, N.J. 



crystals are distinctly scalenohedral, the dominant scalenohe- 

 dron being K: (2131). No instance of a doubly terminated 

 crystal was noted. A strongly developed zone of negative 

 rhomboliedrons connects this type with type II, the forms 

 being identical in both types. Of these the negative rhombo- 

 hedron $.(0221) is developed to a considerable habit. Broad 

 but rough and irregular planes of K. (5052) replace the obtuse 

 polar angles of K: . The negative scalenohedron q i (2161) of 

 tvpe II is present in small development. The positive_scaleno- 

 hedrons % ! (4'8-12-5) and % ! (4\L6'20-9) in the zone [2131-0221] 

 are present as extremely narrow modifications. The termina- 

 tion in crystals of the type is rarely complete, the polar angle 

 of the dominant scalenohedron ordinarily being replaced by a 

 '• built up " rim surrounding a slight depression, which latter is 

 frequently partly filled with rosettes of hematite and prochlo- 

 rite. The following forms were observed : 



I (1010), m. (4041), K. (5052), \.(0S8J), £.(0413), $.(0221), 

 H(055l), 2_.(0-ll-ll-l), K-. (2131), q i (2461), % i (4-8-12-5) and 

 % \ (4-16-20-9). Fig. 3 shows'this combination. 











Table 



of Angles. 



v 











Angle 



Meas- 

 ured 



Calcu- 

 lated 



Angle 



Meas- 

 ured 



Calcu- 

 lated 



0001 



1010 



90 



25 



90 







5491 



4591 



15 



53 



16 



30 



1011 



4041 



31 



10* 



31 



10* 



134L 



0221 



16 



45 



17 



5 



1011 



5052 



23 



30 



23 



19* 



2461 



4261 



30 



33 



30 



39 



0111 



0887 



93 



1 



93 



H 



6395 



6935 ■ 



64 



56 



66 



58 



0111 



0443 



97 



23 



97 



2H 



6395 



9365 



32 



59* 



32 



2 



0111 



0553 



103 



18 



103 



m 



6395 



3695 



69 



13 



68 



17 



0111 



0221 



107 



44* 



]07 



m 



6395 



8-4-12-5 



7 



11 



6 



58 



0111 



0994 



109 



39 



110 



20 



8-4-12-5 



8-12-4-5 



71 



22 



72 



22 



0994 



9904 



104 



H 



104 



i*i 



8-4-I2-5 



12-48-5 



34 



44 



34 



20 



0111 



0o51 



122 



34 



123 



H 



8-4-I2-5 



4-8-12-5 



55 



12* 



55 



20 



0111 



o-ii-ii-i 



129 



13 



129 



20* 



4-8-12-5 



022 L 



16 



46* 



17 



10 



2131 



2311 



75 



9* 



75 



22 



4-16-20-9 



0221 



9 



50 



9 



44* 



2131 



0221 



3 7 



33 



37 



41 



1-13-14-10 



M4-13-108 



2 



16f 



83 



31 



5491 



5941 



66 



m 



66 



42* 



1-13-14-10 



14I3-1-10 



4 



50 



5 



54 



5491 



9451 



52 



13 



52 



11 



T13-14-10 



0443 



3 



55 



3 







Mineralogical Laboratory, N. Y. State Museum, Albany. 



