176 HESSONITE. 



BB on charcoal fuses to a black globule, 

 which, when cold, exhibits on its surface 

 numerous dendrites and globules of silver. 

 Mixed with carbonate of soda, and sub- 

 jected to a continued blast, yields pure 

 silver. 



Dissolves slowly in cold, quickly in hot 

 nitric acid ; the solution, after a while, de- 

 posits tellurite of silver-oxide. 



Localities. The Altai Mountains of 

 Siberia, at the silver mine of Sawodinski, in 

 a talcose rock, associated with Iron Pyrites, 

 Black Blende and Copper Pyrites. JSTag- 

 yag in Transylvania, in right rhomboidal 

 prisms on Quartz. California. 



Brit. Mus., Case 3. 



Hessonite. See Essonite. 



Heteposite, v. KohelU Phillips, Nau- 

 mann. An altered form of Tryphiline. Only 

 occurs in lamellar masses. Colour greenish- 

 grey inclining to bluish-grey, with a waxy 

 lustre ; the faces which are exposed to the 

 air exhibit a semi-metallic lustre and a 

 violet colour. Streak sometimes grey, some- 

 times yellow; after weathering, violet. 

 Scratches glass: easily scratched with a 

 steel point. H. S.G. 3-524 ^ after weather- 

 ing, 3-39. 



Comp. 3(MnEe)P2+5H. 



Analysis, by Djifrinoy : 



Phosphoric acid . . . 41*77 



Protoxide of iron . . . 34-89 



Protoxide of manganese . 17-57 



Silica 0-22 



Water ..... 4-40 



98-85 



BB fuses to a dark brown enamel with a 

 semi-metallic lustre. 



Soluble in muriatic acid, with the excep- 

 tion of a small quantity of : ilica. 



Locality. Chiefly in the quarries at 

 Hureaux in the Haute Vienne. In the peg- 

 matite of the vicinity of Limoges, with 

 Hureaulite. 



Name. From sVsgo?, different. 



Heteposite is distinguished from Triphy- 

 line by its colour; from Triplite, by the 

 lustre of its fractured surface, which in the 

 latter is vitreous. I 



Heteroclink, Dvfrenojj. Heterokline, ^ 

 Breithaupt. Oblique. Occurs in oblique 

 rhombic prisms, with the acute lateral edges , 

 generally replaced; also massive. Colour 

 between iron-black and steel- grey. Lustre j 

 subnietalHc. Streak brownish-black. Frac- | 

 ture uneven to small conchoidal. H. 5. j 

 S.G. 4-562. ! 



HEULA]ST)TTE. 



Comp. Trisihcate of peroxide of man- 

 ganese, or Si M:n^. 



Analysis, by Ewreinow : 



Silica ' 10-02 



Peroxide of manganese . 85 -88 



Peroxide of iron . . . 3-05 



Lime 0-60 



Potash 0-44 



99-99 



BB like peroxide of manganese. 



Jyocality. St. Marcel, in Piedmont. 



Name. From In^oy.pJvzs, in reference to 

 its oblique form of crystallization. 



Hetkromerite, Hermann. A pale green 

 mineral from Statoust ; probably an aftered 

 Idocrase. 



Heteromorphite, Rammelsherg. Occurs 

 in capillary forms resembling cobwebs; 

 also massive. Colour between dark lead- 

 grey and steel-grey ; sometimes with an 

 iridescent tarnish. Lustre dull metallic. 

 H. 1 to 3. S.G. 6-67 to 5-9. 



Comp. PbS + iSb2 S3 = lead 49-8, anti- 

 mony 31-0, sulphur 19-2 = 100. 



Analysis of massive form, from Wolfs- 

 berg, by Poselger : 



Sulphur .... 20-32 

 Antimony .... 32-98 

 Lead 48-48 



101-78 



Fuses instantly in the flame of a candle, 

 with the evolution of white fumes. 



Localities. The Harz at Wolfsberg, An- 

 dreasbergand Clausthal. Freiberg, Schem- 

 nitz, nearNeudorf in Anhalt. Near Bottino 

 in Tuscany. Chonta in Peru. 



Name. From m^«?, another, and y-o^ipyiy 

 form. 



Heterostte, Beudant,') 

 Dana. (From 'in^o?, 

 different.^ ^See Heteposite. 



Heterozite, Dufre- 

 noy, Nicol. 



Heterotomous Felspar, Mohs. See 

 Pericline, 



Heulandite, Brooke, Phillips, Beudant. 

 Oblique ; primary form a right rhombic 

 prism. Occurs in attached crystals and in 

 layers and granular masses, frequently in a 

 globular form, in the cavities of amygda- 

 loidal rocks and in certain metalliferous 

 veins. Colourless or coloured yellowish, 

 brownish, but chiefly flesh- red to tile- red. 

 Lustre vitreous : pearly on planes of cleav- 

 age, and generally translucent, nearly trans- 

 parent when colourless. Brittle. Fracture 



