288 



Forms observed: « = |J00|, strongly predominant and highly 



lustrous; c» =r I 111 I, and r = |102|, well-developed and yielding 



good reflexes; m. = | 110 |, well reflecting; b — | 010 |, and to =r { 122 |, 



narrow, built exaclly measurable; .r = | 112 |, small, often absent. 



Angles; Observed: Calculated: 



a: o =(100): (HI) =* 58°46' — 



0:0 =(111): (111) =* 58 38 

 0:« =(111): (122) = 

 ">:r =(122): (102) =^ 

 a:m = (100):(110) = 

 m:b =(110): (010) = 

 a:r =(100):(202) = 

 r:r =(100): (192) = 

 0:X =(lll):ni2) = 

 ^':&' =(122): (122) ^ 



No distinct cleavage. 



Noticeably dichroitic: on {lOOj yellowish-white for vibrations 



parallel to the c-axis, for those perpendicular to them: pale green. 



The plane of the optical axes is | 001 \ ; the «-axis is first bisectrix. 



The apparent axial angle is very small. 



No exact measurements could hitherto be made of the triclinic 



/^è-salt with 1 H^O, because of the bad crystals only at hand. 



Caesium-ferri-malonate. 



\Fe{C,H,0,\\Cs,^lH,0. 



Pale green, kite-shaped 



crystals. 



Rhombic-bipyramidal. 



a :/^:C = 0,9548:1 : 0,7089. 



Forms observed : 



a = |100|, predominant and 



giving good reflexes; = 



Gaesium-Ferri-Malonate. < p o' > 



like r=:|102}, rather largely 



developed; 7??= |110}, narrow and smaller than r; b = [010\, small 



but well measurable. 



Angles : 



Observed: Calculated: 



