SCHAIiLEB.] 



Minerals from Leon a Heights. 



a = 1.1670 



lg a 0.06707 



lg ao = 11.88537 



lgj>n = 0.11404 r/ii = 0.7080 



pu = 1.3021 



c = 1.519. r > 



lg <■ = 0.1K170 



]g ho = 9.81830 



lg ao = 0.16628 b n = 0.6581 



'/<> = 1.4005 





| g *.= } 9 .98457 

 lg sin /x I 



}■ 9.41814 

 lg cos /x 1 



lg — = 9.94830 A = 0.9051 



? = 0.2019 



a 



3 



z 



U 



'O 



rH 



Miller. 





P 



i 







Vo 





V 



x' 



(Prism) 



(x : y) 



y' 



d' 



tgp 



1 



c 







001 



90° 



00' 15' 



'11 



15° 



11' 



0° 



00' 15' 



11' 



0° 



00' 







2714 









0.2714 



o 





Ooo 



010 







00 



90 



00 







00 



90 



ill) 







(in 



90 



00 











oo 



oo 



3 



« 



t»0 



100 



90 



00 







!(() 



00 







(in 



90 



00 







00 





oo 









4 i 



4 





2oo 



210 



60 



37 











90 



00 



60 



37 



29 



23 



1 



7758 





QO 



I I 



5 



./' 



§00 



320 



53 



06 











t 





53 



06 



36 



54 



1 



3319 









6 



■/« 



oo 



110 



41 



36 















41 



36 



48 



24 







8879 





1 1 



( t 



7 





oo 2 



120 



23 



56 









( 







23 



5(5 



66 



04 







4440 







t i 



8 



«' 



+io 



103 





00 



35 



48 



35 



48 







00 



35 



48 







00 







7211 









0.7211 



9 



V 



+ 10 



101 







58 



19 



58 



19 



t 





58 



19 







1 



62(16 





1 i 



1.6206 



10 



g 



— 10 



205 



90 



00 



15 



01 



To 



01 







To 



01 











2683 







0.2683 



1 1 



t 



— 10 



Toi 







47 



09 



47 



09 







47 



09 







T 



0778 







1.H778 



12 







01 



011 



10 



07- 



57 



04 



15 



11 



56 



39 



8 



29 



55 



42- 







2714 





5196 



1.5436 



13 



r 



+1 



111 



46 



50- 



65 



46 



58 



19 







41 



42 



38 



35 



1 



6206 



1 



5196 



2.2215 



14 



7T 



— 4 



112 



27 



57- 



40 



42 



2T 



58 



37 



13- 



TT 



48 



35 



10 







4032 





7598 



0.8602 



15 



K 



:_! 



335 



30 



33 



46 



38 



28 



17 



42 



21- 



21 



41 



38 



45' 







5381 







9117 



1.0587 



16 



I) 



2 



221 



38 



37 



75 



35 



67 



36- 



71 



47 



37 



11 



49 



11 



o 



4270 3 



0392 



3.8890 



17 



IT 



— 12 



121 



19 



32 



72 



46 



47 



09 



( 





18 



37 



64 



11 



1 



0778 







3.2245 



Physical Properties. — The plane of symmetry is also the 

 plane of the optic axes. A section of the mineral cut' approxi- 

 mately parallel to the clmopinacoid showed that the axis of 

 elasticity nearly parallel to the clino-axis was the axis of mini- 

 mum elasticity. A section cut normal to this axis of elasticity, 

 showed, in convergent light, a biaxial interference figure with a 

 large angle. This figure also showed its positive character. A 

 cleavage piece (parallel to the base) also showed a figure nearly 

 equal in size to the first one seen hut perhaps a trifle larger. 

 This latter figure gave a negative sign, with the quartz wedge. 

 The mineral is therefore positive with the obtuse bisectrix emerg- 

 ing nearly normal to the basal pinacoid. The mineral agrees, 

 therefore, in its optical properties with pisanite. 



The mineral does not occur massive but only in crystals. 

 Concretionary and stalactitic forms were not met with. The 

 mineral is blue in color, vitreous and transparent when free from 



