FLOOK.] 
MINERALS. 
47 
rhombic System; 4th, the Hexagonal or Rhombohedral System; 5th, the 
Oblique or Clinorhombic System ; 6th, the Anorthic System ; and finally, 
Amorphous substances, that either present no crystalline forms, or 
the forms of which, if they be crystalline, are not determinable. In 
the following observations the term "group " will be reserved to con- 
nect Minerals, whether individual species, series, or classes, which pre- 
sent such a community of physical and other characters as imparts to 
them a sort of family resemblance. 
Division I. The Native Elements. 
In Cases 1, ^, 3, and the first half of 4, are arranged such of the Div. I. 
elementary forms of matter as are found occurring in nature in the un- Cases 1, 
combined state. These native elements, which form but a small pro- ^^^■) 
portion of those the chemist has eliminated from the Mineral Kingdom, 
are arranged in sections, of which the first is that of the native metals 
and their alloys. 
Of the series of native metals crystallising in the cubic system the Cases 1, 2 
various forms of Copper, Silver, and Gold are the most important ; and 
crystals of these metals are exhibited, remarkable for the perfection of 
their forms, or conspicuous for their size. The crystallised copper from 
Siberia and from Lake Superior, the silver in crystals from Kongsberg 
and from Freiberg, the suite of specimens of gold from Merionethshire 
and other British localities, two unique nuggets of crystallized gold from CJase 2. 
the Maclvor Diggings, in Australia, and one from California, are espe- 
cially worthy of remark. Besides these, will also be seen native foil 
of silver and of gold: moss-like filamentary aggregations of copper 
and of silver; nuggets, and washed grains of gold, and specimens of 
all these metals, in which a simple crystalline form, by being repeated 
or prolonged along particular axes has built up dendritic, ramose, capil- 
lary, and other singular kinds of structure. Among the specimens of 
gold and of electrum, or argentiferous gold rich in silver, from Tran- 
sylvania, are some worthy of notice from the sharpness of their crystal- 
line forms. Native lead from Sweden, and a crystalline nugget of 
platinum containing metallic iron and presenting magnetic polarity, 
given by H. 1. H. the Grand Duke of Leuchtenberg, are exhibited in 
Case 8. The rhombohedral series of metals includes an isomor- 
phous group — the Arsenoids — namely, Arsenic, Antimony, and Case 3 (i.) 
Bismuth, with which its crystalline form, rather than its chemical 
analogies, associates the rare native element Tellurium. 
Next to the metals are arranged the Metalloids, a section including Case 3 (h"., 
the carbon group and the sulphur group. In the former, elementary 
Carbon is illustrated in its two allotropic mineral forms : Diamond and 
Graphite. Of the Diamond, a large and extremely choice series of 
crystals is exhibited, together with models of the most famous for their 
size and history of the specimens of this, the hardest and most resplen- 
dent of gems. Specimens of the diamonds of South Africa are ex- 
hibited with the rock in which they are found. 
