IRON. : 7S 
figs. 2 to 7; also figs. 8 to 15 on page 6. Fig. 6, a pentag- 
onal dodecahedron, is a common form. Occurs also in imi- 
tative shapes, and massive. 3 
Color bronze-yellow ; streak brownish black. Lustre of 
crystals often splendent metallic. Brittle. H.=6-6°5, be- 
ing hard enough to strike fire with steel. G.=4°8-5:1. 
Composition. Fe 8, = Sulphur 53°3, iron 46°7= 100. 
B.B. on charcoal gives off sulphur, and ultimately affords 
a globule attractable by the magnet. 
Pyrite often contains a minute quantity of gold, and 
is then called auriferous pyrite. Sec under Gold. Nickel, 
cobalt and copper occur in some pyrite. 
Diff. Distinguished from copper pyrites in being too hard 
to be cut by a knife, and also in its paler color. The ores 
of silver, at all resembling pyrite, instead of having its pale 
bronze-yellow color, are steel-gray or nearly black ; and. be- 
sides, they are easily scratched with a knife and quite fusible. - 
Gold is sectile and malleable. 
‘Obs. Pyrite is one of the most common ores on the 
globe. It occurs in rocks of all ages. Cornwall, Elba, 
Piedmont, Sweden, Brazil, and Peru, have afforded magnifi- 
cent crystals. Alston Moor, Derbyshire, Kongsberg in Nor- 
way, are well-known localities. It has also been observed in 
the Vesuvian lavas, and in many other igneous rocks. 
In the United States, the localities are numerous. Fine 
erystals have been met with at Rossie, N. Y.; at many 
other places in that State; also in each of the New England 
States and in Canada; in New Jersey, Pennsylvania, Vir- 
ginia, North Carolina, Georgia, in Colorado, Wyoming and 
the States west. It occurs in ail gold regions, and is one 
source of gold. 
This species is of the highest importance in the arts, 
although not affordimg good iron on account of the diffi- 
culty of separating entirely the sulphur. It affords the 
greater part of the sulphate of iron (green vitriol or cop; eras) 
and sulphuric acid (oil of vitriol) of commerce, and also 
a considerable portion of the sulphur and alum. ‘To make 
the sulphate the pyrites is sometimes heated in ciay retorts, 
by which about 17 per cent. of sulphur is distilled over and 
collected. The ore is then thrown out into heaps, exposed 
to the atmosphere, when a change ensues by which the re- 
maining sulphur and iron become through oxidation sul- 
phate of iron. The material is lixiviated, and partially eva- 
