58 MINERALOGY. 
and laminz in quartz, in taleose micaceous rocks, greenstone, and often 
associated with sulphuret of iron. It is often, however, found in loose soils, 
in sands, and in river beds. Most of the gold recently obtained in 
California is from localities of the kind last mentioned. Pure gold is the 
most malleable of all metals, leaves having been beaten so thin, that 282,000 
are required to be superimposed to make an inch. It melts at 2192° F., and 
is vaporized in the focus of a large burning-glass, or in the flame of the 
oxy-hydrogen blowpipe. 
4. Native Mercury. 
Mercury sometimes occurs native, although it is generally obtained from 
certain ores. It is the only metal which is liquid at ordinary temperatures, 
becoming solidified only at and under — 39° F. The crystals which form in 
this state belong to the monometric system, and are principally octahedrons 
(fig. 33). It occurs as an amalgam, mixed with silver, in different 
proportions. The amalgam is generally stiff, rather brittle, and whitens 
copper when rubbed with it. Mercury mixed with silver presents the 
crystalline forms of both metals, which, at any rate, belong to the same 
system. The principal forms of such crystallization are shown in 
pl. 33, figs. 30, 45, 61, 62, 63. Mercury is obtained principally from the 
mines of Idria in Austria, and Almaden in Spain. Valuable deposits of 
cinnabar, or sulphuret of mercury, have recently been discovered in 
Calitoi nia. 
5. Native Copper. 
Although most of the copper of commerce is obtained from its ores, yet 
it occasionally occurs in enormous masses, as a native metal. It is 
sometimes found crystallized, the crystals belonging to the regular system. 
The principal forms are represented in figs. 24, 30, 36,40, 41. Most 
generally, however, the crystalline structure is not so evident, the metal 
occurring in various amorphous shapes; in veins (jig. 18) and beds in 
granite, syenite, grauwacke, slate, red sandstone, &c. Its principal localities 
are Hungary, Siberia, Brazil, China, Japan, and North America. The 
region about Lake Superior furnishes the largest masses of any known; one 
now in Washington, weighing 3704lbs., and others occurring of such 
enormous size as to present almost insuperable difficulties in the way of 
following out more manageable deposits. A mass was quarried out in the 
Cliff Mines (Lake Superior region), the weight of which was estimated at 
eighty tons. 
6. Native Bismuth. 
This metal rarely occurs pure in nature, being generally combined with | 
arsenic. It occurs in crystals of a rhombohedral form, nearly cubes in 
appearance. Metallic bismuth is of a whitish steel color, with a slight tinge 
of rose-red, and on being broken exhibits a coarsely foliated crystalline 
texture. This is shown in great perfection by melting the metal in a 
crucible, and after allowing a hard crust to form, piercing this, and 
permitting the still liquid portion to run out. Pl. 33, figs. 5 and 10, 
represent the crystallizations thus obtained. Native bismuth is found in 
veins, in gneiss, granite, rarely in clay-slate; generally accompanied by 
488 
