PHYSIOGRAPHY. 23 



Magnetic Iron-Pyrites. 



Lustre metallic. Color intermediate between bronze- 

 yellow and copper-red. Streak dark greyish-black. 



Slight action on the magnet. Brittle. Hardness =3*5 

 . . . 4.5. Sp. gr. =4-631, of a cleavable variety. 



1. Heated in an open tube, it yields sulphureous acid ; upon char- 

 coal, in the exterior flame of the blow-pipe, it is converted into a red 

 oxide of iron. In the interior flame, it melts with a good heat, into a 

 globule, which continues to glow, a few moments after it is withdrawn 

 from the fire. After cooling, it becomes an uneven, black mass. When 

 broken, the fracture is crystalline, arid the lustre metallic, with a yellow- 

 ish color. 



2. Analysis. 

 By HATCHETT. By ROSE. By STROMEYER. 



Iron - - 63-50 - 38-78 - 59-85 ^ - 56-37 



Sulphur - - 3650 - 60-32 - * 40 15 * 43-63 

 The first of these analyses represents a bi-sulphuret of iron ; the oth- 

 ers are mixtures of the two sulphurets. It is often formed artificially in 

 slag*. 



3. It occurs in beds along with other minerals containing iron, with 

 Blende, Copper-Pyrites, and sometimes with lolite. It forms an acci- 

 dental ingredient of several rocks, and crystallizes in their fissures. Its 

 presence has also been ascertained in several meteoric stones. 



4. Small crystals occur at Andreasberg in the Hartz. The compound 

 varieties occur more plentifully. There are cleavable ones at Boden- 

 mais in Bavaria. Other varieties abound in Saxony, Silesia, the Hartz, 

 and Stiria ; also at Cornwall in England. The cleavable variety is found 

 at Munroe, (Conn ) imbedded in Quartz, and attended by numerous 

 ores ; also in the next town, Trumbull, in a vein of Topaz and Fluor. 

 The uncleavable variety occurs in Vermont, at Stafford and Shrewsbu- 

 ry ; and at several places in Massachusetts ; in which localities, it is at- 

 tended by Iron Pyrites. 



5. It is employed, along with Iron Pyrites, in the manufacture of cop- 

 peras and sulphuric acid. 



MALACHITE. (See Blue Malachite ard Green Mala- 

 chite.) 



MALACOLITE. (See Pyroxene.) 



