PLATE XIII. 
Figs. 1—10.—Gold. 
1. Native Gold , in roundish particles, as if melted together, imbedded in and encrusted on a finely granular reddish 
quartz, from San Francisco, California. 
2. Crystal of Gold, a regular octahedron, the primary form perfectly formed above, with roundish melted grains below, 
of the natural size as it was, according to F. Alger, found a few years ago in California. This native gold contains 87 5 to 
88-5 of gold, the rest is silver with traces of copper and iron. 
3. The same , a cube with truncation of the angles (octahedron), and of the edges (rhombic dodecahedron ) as some¬ 
times found, but smaller and more irregular, in Brazil. 
4. Native Gold, in thin, crystalline, leaf-like laminae, on reddish quartz, from Vbrospatak in Siebenburg. This contains 
6049 of gold, and 38-74 of silver. 
5. Gold Nugget, of a rounded oblong form in a reduced scale, declared to be the largest piece of native gold yet 
found at Victoria diggings in Australia, weighing 27 pounds 6 ounces, and 11 inches in length by 5 broad. 
6. Small Nugget of Gold from the clayey sandy alluvium of the Gold Coast, West Africa. It contains 86-80 of gold, 
and 11 -30 of silver, with traces of copper. 
7. Grains of Gold of different forms and sizes, all flat and bearing marks of attrition, from the gold sand of Ban 
F rancisco. 
8. Gold-dust as it is most frequently obtained by washing, from the foot of the. Urals. 
9. Smooth Gold, in grains of different size, imbedded in a reddish finely granular quartz, trom A ictoria, Australia. 
10. Telluric or Graphic Gold, a combination of 59 97 of tellurium with 26-97 of gold and 11-47 of silver ; one of the few 
specimens of actually mineralised gold, from Offenbanya in Siebenburg, Transylvania. The crystals are small right rhombic 
prisms, arranged in a radiated manner, firmly united to reddish quartz. 
Figs. 11—13. —'Platinum. 
11. Native Platinum, in small, lenticular, polished granules, from Choco in Brazil, where it is obtained along with gold, 
etc., by washing the sand. It contains 8G-16 platinum, 8-03 iron, l - 09 iridium, 2-16 rhodium, 0'35 palladium, 0"97 osmium, 
0-40 copper. 
12. Native Platinum, a roundish mass, above, as it were polished, with irregular cavities at the side, which contain a 
darkish grey substance, the irite of Hermann, consisting of the oxides of iridium, osmium, iron and chromium, 2^ oz. in weight, 
from Nisei me Tagilsk, in the Urals. 
13. Native Platinum , of the natural size, almost two pounds in weight, from the same locality. 
Fig. 14.—Iridium. 
14. Osm-iridium, or Tridosmine, in small hexagonal plates and irregular flattened grains, from the platinum sand of the 
same place. 
