s< nAr,LEB.] Minerals from Leona Heights. 197 



bruised below this form, so that it is possible that another 

 dome, large and triangular in shape, possibly { 301 \ , was 

 originally present. 



B == +f = {332}. This pyramid was observed on two frag- 

 ments. It gave good reflections. 



Figs. 1-3, Plate 19, show some of the combinations observed 

 on these crystals. 



Besides these forms, given above, a few vicinal ones were 

 observed on crystal No. 6, of which the symbols calculated from 

 the measurements and the probable true symbols, are given 

 below. 



Calculated Probable 

 symbols. symbols. 

 {5.1.12} {102} 

 {7.14.2} {120} 

 {5.12.5} {121} 



The habit of the crystals is prismatic with the unit prism 

 and the base the predominating forms. 



The following table shows the combinations of the forms on 

 the crystals: 



No cbvilivdkvxqj o r B <r 



1 c — vi — — — — — — — — — — — — 



2 c — m — — — — — — — — — r B — 



3 c b m — — — — — — — — o — — — 



4 e — m — — — — — — — — — — — — 



5 c — m — w d k v x q j — — — — 



6 c b m I w — — — — — — — — — cr 



8 c b m I x 



9 c — m — — — — — — — — — )• B — 



The axial ratio, a:6:c = 1.1823 : 1 : 1.5421; /? = 104° 14', was 

 calculated from the three following measurements of interfacial 

 angles, in preference to a calculation from the averages of p'a, r/o 

 and e' ' , since the polar adjustment was not perfect. 



c : m = (001) : (110) = 80° 42' 

 c, : o = (001) : (011) = 5(5° 13' 

 m ■ m'= (110) : (110) = 97° 47' 



This ratio agrees very closely with the one obtained by 

 Zepharovich,* which is 



a : 6 : c = 1.18128 : 1 : 1.5427; /? = 104° loV. 

 * Zeitschr. Krys. 1880, 4, 107. 



