8 A POPULAR EXPOSITION OF THE 
(Figs. 13 and 14), and scalenohedrons (Fig. 15), are included under 
this system. Graphite, Red Silver ores, Cinnabar, Specular Iron 
Ore, Corundum, Quartz, Beryl, Apatite or ;phosphate of lime, Cal- 
a o © 
Fie: 10. Fie. 11. Fig. 12. 
5 
Fig. 13. Fia. 14. FIG. 15. 
) 
—o 
careous Spar, Dolomite, and Carbonate of Iron, are some of the 
principal minerals which belong to it. 
The Trimetrie or Rhombic system.—This system includes right- 
rhombic prisms, rectangular prisms, rhombic octahedrons, &c., and 
their combinations. Fig. 16 is a rhombic prism ; figs. 17 and 18 are 
Sea 
Peat 
Fira. 16. Fig. 17. 
combinations beionging to this system. White iron-pyrites, mispickel 
or arsenical pyrites, native sulphur, topaz, staurolite, arragonite, 
heavy spar, celestine, and Epsom salt, are some of the principal 
minerals which belong to this group. 
The Monoclinic or Oblique Rhombie system.—Rhombic prisms and 
pyramids, and rectangular prisms and pyramids, with oblique or 
sloping base, belong to this system. ‘Figs. 19 and 20 are monoclinic 
