Dec, 1908. Mineralogical Notes 133 



centimeters, and possess a yellow tinge. They may be described as 

 having a wedge-shaped form, this being chiefly produced by the 

 development of the prism M (410). 



Another prismatic habit is characterized by a normally developed 

 unit prism combined with extended basal and macropinacoids. 

 Several pyramids also usually round the edge between the basal plane 

 and prism. These crystals are as a rule transparent and colorless 

 and rather small in size, their length in the direction of the vertical 

 axis being about 4 millimeters, and in the direction of the macro- 

 axis, about 7 millimeters. Fig. 1, PI. XLV (Mus. No. M 9573) illus- 

 trates this habit. 



The only remaining habit to be noted is a pyramidal one. Crys- 

 tals of this habit are as a rule of simple development and are com- 

 posed principally of the pyramid y (122) with minute basal planes and 

 macro or brachydomes. One crystal of this type also shows small 

 planes of the unit prism. These crystals have average lengths in the 

 direction of the vertical axis of from 5 to 10 millimeters. On one 

 specimen (Mus. No. M 9569) represented in Fig. 4, PL XLVT, the 

 crystals have a milk-white color, while those of another specimen 

 (Mus. No. M 9576) represented in Fig. 5, PI. XVLI, are more nearly 

 transparent and dark colored. The occurrence of the macrodome 

 on one and brachydome on the other is also notable. One speci- 

 men (Mus. No. M 9677) exhibits a single large crystal possessing a 

 pyramidal habit, but owing to the rounded nature of the planes the 

 symbol could not be determined. The crystal is 4.5 centimeters in 

 length, partially opaque, and of a dark yellow color. Another habit 

 of occasional occurrence is produced by a combination of a pyramid 

 and prism in about equal proportions. Crystals of this type (Mus. 

 No. M 9581) are illustrated in Fig. 6, PI. XLVI. They are not as a 

 rule doubly terminated, but are so occasionally. Generally they are 

 small, about .7 of a centimeter being an average length. These crys- 

 tals are also as a rule transparent and colorless. 



A total list of the forms observed on the Eureka anglesites is as 

 follows : 



(230) r (112) 



(120) z (111) 



(011) r (221) 



(102) p (324) 



(104) y (122) 



ft (124) 



