CHONIKRITE. 



ish. Fracture sub-conchoidal, uneven. Ac- 

 quires resinous electricity by friction. 

 H. 6 to 6-5. S.G. 3-12 to 3-19. 



Comp. Mg* Si with part of the oxygen 

 replaced by fluorine, and part of the mag- 

 nesia by protoxide of iron. 



Analysis of a reddish-yellow variety from 

 Eden, near New York, by Thomson : 

 Magnesia .... 54-64 



Silica 36-00 



Protoxide of iron . . 3-75 



Fluorine .... 3-97 

 Water . . . .1-62 



99-98 



BB when strongly heated yields hydro- 

 fluoric acid, loses its colour and fuses at the 

 edges : with borax it fuses slowly but com- 

 pletely, to a clear glass, tinged by iron ; but 

 by interrupted hlowing ov fla7ning, the glass 

 becomes opaque and crystalline. 



Soluble in muriatic acid, with separation 

 of gelatinous silica. 



Localities.— Scotch. Loch Ness, in gran- 

 ular carbonate of lime, with Magnetic and 

 Arsenical Pyrites. — b-ish. Near Gweedore, 

 CO. Donegal, in crystalline Dolomite. — Fo- 

 reign. The largest and most cr^-stalline 

 masses occur a mile north of Sparta in New 

 Jersey, and near Edenville in New York ; it 

 is also met with massive and in grains, 

 associated with Pargasite near Abo, in 

 Pargas, Finland. Aker and Galsjo in Swe- 

 den. Tabu in Wermland. Saxony. Ach- 

 matowsk in the Ural, and at the mines of 

 Schisminsk with red Spartite. 



Name. From xovSgo? a grain, in allusion 

 to its granular structure. 



Brit. Mus., Case 58. 



3I.P. G. Horse -shoe Case, Nos. 921, 921.* 



Chonikrite, v. Kohell. A variety of 

 Pyrosclerite, with which it is associated, in 

 Elba. Massive. Colour white with shades 

 of yellow and grey. . Lustre glimmering 

 or dull. Translucent : often only at the 

 edges. Fracture conchoidal. H.' 2 to 4'. 

 S.G. 2-9L 



Comp. Hydrosilicate of alumina, mag- 

 nesia, and lime. 5(Ca Mg Fe)2 Si + 2A1 



fci + 6H.=lime 12*85, magnesia 23 35, pro- 

 toxide of iron 1*47, alumina 17-14, silica 

 35-19, water 9-00 = 100-10. 

 Analysis, by v. Kohell : 



Lime 12-60 



Magnesia .... 22-50 

 Protoxide of iron . .1-46 



Alumina .... 17-12 i 



CHROME OCHRE, 



81 



Silica 

 Water 



35-69 



9-00 



98-37 



BB fuses with tolerable facility to a grey- 

 ish-white glass, with the evolution of bub- 

 bles of gas ; with borax melts slowly to a 

 globule covered with iron. 



Soluble in muriatic acid without gela- 

 tinising. 



Locality. Elba, in irregular masses in 

 Serpentine. 



Name. From x^vs^z, fusion, and y-ei'^o;, test, 

 in allusion to its difi"erence from some allied 

 minerals with regard to fusibility. 



Brit. Mus., Cases 27—31. 



Chrismatine, Germar. A mineral allied 

 to Ozocerite, from a red argillaceous sand- 

 stone in the coal formation at Wettin, near 

 Halle. It is of an oil- green or yellowish 

 colour, shining and translucent to trans 

 parent. It becomes soft at 55° to 60° R, 

 (156° to 167° F.) Burns with flame without 

 smell. 



Christianite, Lescloiseaux. The name 

 given by Descloiseaux to the Harmotome 

 from Stempel near Marburg, and small, 

 colourless, translucent crystals from Iceland, 

 referrible to a right rhomboidal prism. 

 The crystals never occur detached, but al- 

 Avays pressed closely together, forming mam- 

 miliary groups or radiating crests like 

 certain varieties of Prehnite. Fragile. 

 Easily scratches glass. S.G. 2-2. 



Analysis, from Stempel, by Genth : 

 Silica ..... 48-17 

 Alumina .... 21"11 

 Peroxide of iron . . . 0-24 

 Lime ..... 6-97 

 Potash . . , . .661. 

 Soda ..... 0-63 

 Water . , . . .16-62 



100-35 



Localities. The Bay of Dyrefiord on the 

 Avest coast of Iceland, in cavities ia amyg- 

 daloid. 



The name Christianite was also given b}' 

 Monticelli to the Anorthite of Vesuvms, in 

 compliment to Prince Christian of Den- 

 mark. 



Chromate of Iron, Phillips. See Chro- 

 mic Iron. 



Chromate of Lead, PhilUps. See Cro- 



COISITE. 



Chromate of Lead and Copper, Phil- 

 Ups. See Vauquelinite. 



Chrome Ochre, Hausmann, Nicol. A 

 clayey substance, occurring ia a pulverulent 



G 



