242 MISPICKEL. 



Analysis, by Scacchi : 



Sulphuric acid . . . 56'93 



Potash 3u"57 



Alumina .... 0'38 

 Water . . . . . 6-12 



100-00 

 MispiCKEL. Rhombic. Occurs crystal- 

 lized in right rhombic prisms, parallel to 

 •whose plaues it may be cleaved; also 

 massive, acicular, and columnar. Colour 

 tin-white. Lustre metallic. Streak black- 

 ish-grey. Brittle. Fracture uneven. Gives 

 a few sparks with steel, emittino^ an arseni- 

 cal odour. H. 5-5 to 6. S.G. 6-13. 



Fig. 291. 



Camp. Arsenide with bisulphide of iron, 

 or Fe As + Fe S2 = iron 33"54, arsenic 46*58, 

 sulphur 19-88 = 100. 



Analysis, by Stromeyer, of crystals from 

 Freiberg : 



Iron 36-04 



Arsenic .... 43-42 



Sulphur . . . .21-08 



100-00 



BB on charcoal emits strong arsenical 

 fumes, and fuses to a globule which behaves 

 like Magnetic Pyrites. 



Dissolves in strong nitric acid or aqua- 

 regia, with separation of sulphur and arseni- 

 ous acid. 



Localities. English Common in Corn- 

 wall at Botallack, Levant, Cook's Kitchen, 

 Huel Tolgus, Dolcoath, Carn Brea, Huel 

 Vor, Calstock, United, Huel IMartha, and 

 other mines. Several mines near Tavistock, 

 Devonshire, in very fine crystals. Brandy 

 Gill, Carrock Fells, and Goldscope Mine, 

 Cumberland. — Scotch. Near Loch Ness; 

 Stonehaven, Aberdeenshire. — Foreign. 

 Abundant at Freiberg and Munzig in Sax- 

 ony. Andreasberg in the Harz. Joachims- 

 thal in Bohemia. Tunaberg in Sweden. 

 In gneiss at Franconia in New Hampshire, 

 and at Tennessee, U.S. 



Mispickel occurs chiefly in lodes in 

 crystalline rocks, associated with Iron and 

 Copper Pyrites, Blende, and ores of silver, 

 lead and tin. It was formerly worked in 

 Cornwall as an ore of arsenic, much of the 

 white arsenic of commerce being obtained 

 from it. 



MOCHA-STONE. 



For varieties of Mispickel see Danaite, 

 and Plinian. 



Brit. Mus., Case 12. 



M. P. G. Principal Floor, Table-case 14 ; 

 Wall-case 14 (British); 19 (Foreign). 



MiSY, Hausmann. An impure sulphate 

 of peroxide of iron, mixed with other sul- 

 phates, occurring in opaque, pulverulent 

 masses of a sulphur- or lemon-yellow colour. 



Comp. 4FeS + KS + 9H. 





Analysis, by List : 





Sulphuric acid . 



. 42-922 



Peroxide of iron 



. 30-066 



Oxide of zinc . 



. 2-491 



Magnesia . 



. 2-812 



Potash 



. 0-318 



Water 



. 21-391 



100-000 



Locality. Rammelsberg Mine, near Gos- 

 lar in the Harz. 



Name. Used by the miners. 



Brit. Mus., Case 55. 



Mysy is a stone or ore described by Pliny 

 to be a"^kind of Pyrites. 



" You shall know it by these signes : 

 breake it (for crumble it will) there appeare 

 within it certain sparkes shining like gold : 

 and in the braying or stamping, it run- 

 neth into Chalcitis. This Mysy is the mi- 

 nerall that they put to gold ore, when it is 

 to be tried and purified. . . The best is that 

 which is found in the mines and forges of 

 Cypresse." — Pliny, book xxxiv. 



MizzoNiTE, Scacchi. A variety of Meio- 

 nite, from which it differs principally in not 

 intumescing so much before the blowpipe, 

 and in being acted on by acids in a less de- 

 gree. 



Locality. Monte Somma, n-sar Naples. 



Mocha-stone. Mocho-stone, Mo- 

 CHOS, Kirwan. A white translucent variety 

 of Agate, containing brown markings re- 

 sembling trees and vegetable filaments, 

 occasioned probably by the infiltration of 

 iron or mtinganese. It is chiefly brought 

 from Arabia, whence the name Mocha-stone. 

 " The variegated stones with landscapes, 

 trees and water, beautifully delineated, are 

 found at Cubberpunj (the five tombs), a 

 place sixty miles distant" from Rajpipla 

 in Guzerat. — Forbes' Oriental Mewmrs, vol. 

 ii. p. 20. 



This stone is also met with in Wicklow. 



Name. Perhaps the name Mocha-stone or 

 Mochos-stone is a corruption of Moschus- 

 (or moss-) stone, 



Brit. Mus., Case 23. 



