HELIOTROPE. 

 Analysis, by Kersten : 

 Arseniate of lead . . . 60-10 

 Chloride of lead . . . 10-29 

 Phosphate of lime . .15-51 

 Arseniate of lime . . .12-98 



98-88 



BB fonns a white friable mass, but 

 affords no arsenical odour. 



Locality. Longbanshytta, in Sweden. 



Heliotrope, See Bloodstone. 



Helleflinta of tlie Swedes. A compact 

 and massive variety of Felspar, of a deep 

 flesh-red colour, and with a peculiarly waxy 

 texture, from Gryphyttan in Sweden. 



Hemiinth, G. H^Otto Volger. A variety 

 of Chlorite, occurring in Felspar and Quartz. 



Helvin, or Helvine, Haiiy, Phillips, Wer- 

 ner. Cubical. Primary form a regular 

 tetrahedron. Occurs in'small tetrahedrons, 

 with their solid angles replaced. Colour 

 wax -yellow, inclining to yellowish-brown 

 or siskin-green. Subtranslucent. Lustre 

 vitreous inclining to resinous. Streak white. 

 Fracture uneven. H. 6 to 6-5. S.G. 3-1 to 



Fig. 227. 



Fig. 228. 



Comp. Silicate of glucina, and protoxide 

 of manganese. 



Analysis, by C. Gmelin : 



Silica 33-25 



Glucina and alnmina . . 12-03 

 Protoxide of manganese .31-82 

 Protoxide of iron . . . 5-56 

 Sulphide of manganese * 14-00 

 Water 1-16 



97-82 

 BB in the inner flame fuses with ebulli- 

 tion, and forms a turbid yellow globule ; in 

 the outer flame fuses with greater diflicult}', 

 and acquires a deeper colour. Dissolves 

 slowly in borax, forming a clear glass, 

 which, till the whole of the substance is 

 dissolved, has a yellowish tinge arising from 

 the presence of sulphide of sodium, but after 

 the solution is complete, it appears colourless 

 in the inner flame, and amethyst- red in the 

 outer. Dissolves in muriatic acid with 

 evolution of sulphuretted hydrogen gas and 

 separation of gelatinous silica. 

 Localities. Schwarzenberg in Saxony, 



HEMATITE. 173 



with Garnet, Quartz, Fluor and Calc-spar. 

 Hortekulle, near Modum in Norway. 



Name. The name was given by Werner, 

 in allusion to the colour; from '^X/»?, the sun. 



Brit. Mus., Case 37. 



M. P. G. Horse-shoe Case. 



Heimatite. Dana, Brooke Sf 3Iiller. 

 Hexagonal ; primary form an acute rhom- 

 bohedron : also occurs columnarj granular, 

 botryoidal, and stalactitic : lamellar ; friable 

 or compact. Colour dark steel-grey or iron- 

 black ; of earthy varieties red.' Lustre 

 metallic, sometimes splendent, or earthy. 

 Opaque, but faintly translucent, and of '^a 

 blood- red colour by transmitted light when 

 in very thin laminae, as it occurs in mica- 

 ceous iron-ore. Streak cherry-red or reddish 

 brown, which serves to distinguish it from 

 Magnetite. Fracture subconchoidal, uneven. 

 Sometimes feebly magnetic. H. 5*5 to 6-5. 

 S-G._4-5 to 5-3. 



Distinguished from Magnetite by its 

 cherry-red or reddish-brown streak. 



Comp. Peroxide (sesquioxide) of iron, or 



Fe = iron 70, oxygen 30-100. 



BB alone infusible ; with soda on char- 

 coal, it sinks together with the soda into 

 the charcoal, and is easily reduced to a 

 metallic powder, which may be separated 

 from the charcoal'by pounding and leviga- 

 tion : with borax forms a green or yellow 

 glass. 



Readily soluble in hot muriatic acid, 

 when reduced to powder. 



Localities. — British. This ore is largely 

 worked, and aflfords much of the iron manvx- 

 factured in this and other countries. The 

 Hematite of North Lancashire and West 

 Cumberland produces not less than a mil- 

 lion tons per annum. It is supposed that 

 the Hematite which occurs in the Carboni- 

 ferous Limestone of the Mendip Hills in 

 Somersetshire, and the so-called brown He- 

 matite of the Forest of Dean in Gloucester- 

 shire were worked by the Romans during 

 the period when they held possession of these 

 islands. It is obtained also in Cornwall; 

 Devonshire ; in Glamorganshire, in the dis- 

 tricts of Llantrissant and Llanhary, near 

 Cowbridge, and at Newton Nottage, near 

 Bridgend ; in North Wales, and in the neigh- 

 bourhood of Glasgow. — Foreign. Hematite 

 is found in France, Spain, Germany, and 

 Russia, where the mines of Goumeschefskoi 

 contain much of it. 



The mines of Elba have been worked 

 from a very remote period, and the island 

 is described by Virgil as being " Insula in- 

 exhaustis chalybdum generosa metallis." 



