ORLEK I. UHOMBOHEDEAL LIME-HALOIDE. 87 



134. 2. Axis of revolution parallel, face of com- 

 position perpendicular to a terminal edge of R. 

 The regular composition in faces parallel to R 1, 

 Fig. 130., takes place also in massive varieties, 

 and then more or less thick lamina? of the two in- 

 dividuals alternate with each other, as in Fig. 131. 

 The frequent occurrence of those well known striae 

 upon the faces of cleavage, parallel to the horizon- 

 tal diagonal of the rhombs, depends upon this mode 

 of regular composition. The faces of composi- 

 tion, also those in the direction of R oo, used 

 formerly to be considered as faces of cleavage. 



Implanted globules ; stalactitic, botryoidal, fruti- 

 cose shapes: surface uneven, drusy, rough or smooth, 

 composition columnar, more or less distinct, straight, 

 diverging, and of various sizes. Stalactitic and 

 botryoidal varieties are often composed a second 

 time of curved lamellar particles, conformably to 

 the surface of the imitative shape, the faces of 

 composition being uneven and rough, or irregu- 

 larly streaked in a longitudinal direction. Mas- 

 sive : 1. Composition columnar, the individuals 

 being straight, parallel, or diverging, very often of 

 remarkable delicacy. In a second composition, glo- 

 bular masses are produced, consisting of curved la- 

 mellar particles, the faces of composition between 

 the latter often being smooth. These globules are 

 again joined in a third composition, producing gra- 

 nular masses, between which the faces of compo- 

 sition are uneven and rough. 2, Composition gra- 



