94 



IJECORDS OF THE AUSTRALIAN MUSEUM. 



Magnet mineral lias three mure forms. The table of angles below 

 gives the measured and" calculated values for I. and also the 

 observed angles belonging to forms on II. and III., as, owing to 

 the small size and imperfect development of the crystals, on the 

 goniometer it was impossible to distinguish the reflections belong- 

 ing to the se\'era] indi\iduals, and it was mainly from the angular 

 measurements that the twiiniing structure was deduced. 



Habit ii. (PL xx, %. 2). Tlie crystals with this habit differ 

 from the others mainly in having a large basal plane, and in being 

 greatl}'' shortened along the ^'ertical axis, the result being flat 

 tables approaching the hexagonal form. That they are trillings 



