ART. 2. 



PETROLOGY AT GOOSE CREEK SHANNON. 



61 



South of the central part of the quarry face an apKte dike from 

 2 cm. to. 3 cm. wide is cut by later seams filled with diopside and 

 where these diopside seams widen they have a central layer of pur- 

 plish-gray axinite. In places the 



axinite seams contain minute vugs 

 lined with acute wedge-shaped ax- 

 inite cr^^stals of purplish-brown 

 color. The central portion of these 

 vugs is filled with cottony white 

 hornblende which contains embed- 

 ded perfect crystals of axinite and 

 a few long prismatic crystals of epi- 

 dote. One such axinite-lined cav- 

 ity was filled with a white mineral 

 which, when examined microscopi- 

 cally, was found to contain numer- 

 ous included colorless hornblende 

 fibers. This white mineral which 

 is biaxial, positive with 2V small, 

 r>v pronounced, has a perfect 

 cleavage perpendicular to the 

 acute bisectrix and is doubtless 

 apophyllite. Its refractive index, 

 i3 is 1.538. 



The axinite crystal which was 

 measured was one of the perfect 

 individuals suspended on horn- 

 blende fibers. It has the form 

 and habit shown in figure 9 and 

 gave the following measurements : 



Fig. 9.— Axinite. Showing common h.\bit of 



CRYSTALS FROM QOOSE CREEK. ORTHOGRAPHIC 

 AND CLINOGRAPHIC PROJECTION ON C (010)" 



Measurements of axinite froyn Goose Creek. 



Quality 

 description. 



Fair 



Good 



Very poor 



Poor 



Very Good _ _ 



Poor 



Medium 



Fair 



Verj^ good ._ 



Measured. 



27 



135 27 



152 36 

 156 04 

 147 55 

 140 41 

 169 33 



153 39 

 7 58 



90 00 

 90 00 

 90 00 

 90 00 

 90 00 

 90 00 

 90 00 

 68 17 

 45 12 



Calculated. 



00 

 135 24 

 151 23 

 158 38 

 147 03 

 139 58 



n.c. 

 153 49 



7 58 



90 00 

 90 00 

 90 00 

 90 00 

 90 00 

 90 00 

 90 00 

 68 32 

 45 16 



