PHYSIOGRAPHY. . 123 



Chabasie. 



wine yellow or flesh-red color, in crystals of various sizes, and often 

 highly modified : they exist in the cavities of amygdaloidal rocks, accom- 

 panied by Analcime, Calcareous Spar and Heulandite. In the United 

 States, Chabasie is occasionally met with in the trap region of the Con- 

 necticut river; also in seams between the layers of a mica slate rock at 

 Chester, (Mass.) and at Baltimore, (Maryland,) under similar circum- 

 stances. It occurs on gneiss with Stilbite, at Hadlyme, (Ct.) 



CHALKOLITE. (See Uranite.) 

 CHALKOPYRITE. (See Yellow Copper-Ore.} 

 CHALKOSIDERITE. 



In very thin tabular crystals : stalactitic and drusy. Frac- 

 ture fibrous and foliated. Color green, mostly yellowish. Lus- 

 tre pearly. " Half-hard." Sp. gr. =3-392. 



CHALKOSINE. (See Vitreous Copper.) 



CHALKOTRICHITE. 



The capillary variety of Red Copper-ore, q. v. 



CHAMOISITE. 



Massive ; composition impalpable, or oolitic. 



Color greenish-grey. 



Scratched by the point of a knife. Sp. gr. == 3-0 ... 3-4. 



1. It yields moisture when heated in a glass tube, at the same time 

 assuming a blacker color, and becoming more magnetic. It dissolves in 

 the strong acids, leaving behind a portion of gelatinised silica. 



2. Analysis. 

 By BERTHIER. 



Silica .... 14.3 



Alumina .... 7.3 



Protoxide of iron .... 60-5 

 Water .... 17.4 



In addition to the above, it contains variable proportions of carbonate 

 of lime and magnesia. 



3. It occurs in beds of moderate thickness in the limestone mountain 

 of Chamoison in the Vallais, France. 



4. It is explored with profit as an ore of iron. 



5. The Chamoisite appears to be an impure variety of Magnetic Iron- 

 Ore. 



