1917] Eaklc: Minerals Associated with Crystalline Limestone 335 



occur in direct association with garnet and vesuvianite. They are 

 elongated parallel to the &-axis and have one end terminated by fairly 

 good faces. The forms observed on these crystals are : 



a (100) m (110) v (101) s (201) 



c (001) x (120) a (T02) p (111) new 



g (011) (320) t (T01) 



■ 



The orthopinacoid and base are broad while the domes are very 

 narrow; this gives the crystals an appearance of elongated square 

 prisms. One* crystal had a rough face of the front unit pyramid, 

 which is a new form for wollastonite. Figure 1, plate 23, shows this 

 type. The angles obtained with the two-circle goniometer and those 

 calculated are as follows : 



Measured Calculated 



Forms 





<P 





P 





<t> 



P 



C 001 



90°00' 



5° 34' 



90°00' 



5° 30' 



a 100 



90 



00 



90 



00 



90 



00 



90 00 



m 110 



43 



40 



90 



00 



43 



39 



90 00 



x 120 



25 



31 



90 



00 



25 



30 



90 00 



s 320 



55 



10 



90 



00 



55 



03 



90 00 



v 101 



90 



00 



45 



21 



90 



00 



45 35 



a T02 



90 



00 



19 



36 



90 



00 



M 03 



t T01 



90 



00 



39 



13 



90 



00 



39 35 



S 201 



90 



00 



60 



03 



90 



00 



60 14 



g on 



4 



42 



46 



36 



5 



39 



44 12 



p in 



47 



10 



53 



36 



46 



29 



54 34 



The third structural type is granular and very unusual for wol- 

 lastonite. Large masses of snow-white, fine-granular wollastonite 

 occur in the white limestone of the North Star quarry of Sky Blue 

 Hill. The material is loosely coherent and friable ; specimens can 

 readily be crushed between the fingers into fine grit and glassy grains. 

 An analysis of this unusual variety gave the composition : 



Si0 2 51.77% 

 Fe,.0 3 2.12 



CaO 44.85 

 Ign. 1.02 



99.76 



The general tendency of wollastonite is to crystallize in long 

 columnar forms ; when found occurring as a fine granular mass it 

 must mean a peculiar condition of crystallization. Wollastonite 

 usually occurs imbedded in limestone as inclusions, but massive 

 boulders of this granular variety are quarried containing no associated 



