MINERALS AND GEOLOGY OF CANADA. ‘a 
with figures of a few of their more common forms and combinations, 
are given in the annexed tabular view. 
The Monometrice or Regular System.—This group includes the 
cube (Fig. 1), the rhombic dodecahedron (Fig. 2), the regular octa- 
hedron (Fig. 3), trapezohedrons or leucitoids (Fig. 4), pentagonal 
dodecahedrons (Fig. 5), &c. Fig. 6 is a combination of the cube and 
Jao ¢©@ 
Fie. 1. Fia. 2. Fig. 3. FIG. 4. 
Fia. 5. FIa. 6. Fria. 7. 
octahedron ; Fig 7, a combination of the cube and pentagonal dode- 
cahedron. Native gold, silver, copper, iron pyrites, galena, magnetic 
iron ore, garnet, fluor spar, rock salt, and numerous other minerals, 
erystallize in this system. 
The Dimetric or Square-Prismatic system.—This includes, princi- 
pally, squaré-based prisms and pyramids (or octahedrons), and their 
combinations. Figures 8 and nine are examples of Dimetric crystals. 
Fria. 8. Fi4G. 9. 
Amongst minerals, Copper Pyrites, Tin-stone, Zircon, and Idocrase, 
may be cited as belonging to the group. 
The Hexagonal system.—Regular six-sided prisms (Fig. 10) and 
pyramids (Fig. 11), combinations of these (Fig 12), rhombohedrons 
