63 CAT SILVER. 



are preferred, but the value of the stone 

 depends more upon its play of colour than 

 upon the greater or less amount of its trans- 

 parency. 



Catlinite. a reddish variety of clay- 

 stone from the Coteau des Prairies, west of 

 theMississippi,which is carved into tobacco- 

 pipes by the North American Indians. It 

 is named by Dr. Jackson after Catlin, the 

 American traveller, who was the first white 

 man allowed by the Indians to visit the 

 quarry where it is found. 



Brit. Mus., Case 26. 



M.P.G. Horse-shoe Case, No. 4. 



Cauliflower. The name given by the 

 quarrymen in the Isle of Portland to stalag- 

 mitic carbonate of lime, found in the joints 

 of Portland Stone. 



Cavolinite, BIonticellL See Nephelixe. 



Cawk. An opaque, massive, earthy- 

 looking variety of Barytes, of a dirty -white 

 or reddish colour, very common in Derby- 

 shire with Galena. It is also found at 

 Grassington, in Yorkshire, and in Stafford- 

 shire. 



Brit. Mus., Case 52. 



Celestin, iVerner. Celestine, Jame- 

 son, Werner. Rhombic. It occurs massive, 

 fibrous, stellated, and crystallized ; the pri- 

 mary form being a right rhombic prism. 

 Colour white, grey, seldom yellow or red- 

 dish, but sometimes of a delicate blue, 

 sometimes approaching to sky-blue, Avhence 

 the name Celestine. Lustre shining. Trans- 

 parent to subtranslucent. Stream white. 

 Very brittle. H. 3 to 3-5. S.G. 3-.95. 



Fig. 92 



Fig. 94. 



Comp. Sr S = sulphuric acid43'6, strontia 

 5G-4=100, often mixed with carbonate of 

 lime, barytes, or oxide of iron. 



BB decrepitates and melts into a white, 

 opaque, friable enamel. When reduced to 

 powder, it phosphoresces on red-hot iron. 



CENTRALASSITE. 



Localities. Fine transparent prismatic 

 crystals are found associated with Sulphur 

 and Gypsum in the sulphur mines of Sicily ; 

 it is also met with at Bex, in Switzerland ; 

 in the Green Marls of Montmartre and Beau- 

 mont (Dordogne), and in Chalk Flints at 

 Meudon, in France ; Conil, inSpain ; Pschow, 

 in Upper Silesia; and in straight fibrous 

 concretions, of a blue colour, imbedded in 

 clay at Dornberg near Jena ; and at Franks- 

 town, in Pennsylvania. It occurs in consi- 

 derable quantities in New Red Marl, in the 

 neighbourhood of Bristol, where it is made 

 into Nitrate of Strontia, which forms the 

 basis of the red fire used in pvrotechny. 



Brit. Mus., Case 53.. 



31. P. G. Horse-shoe Case, Nos. 266 to 

 280 ; also No. 147. Upper Gallery, Wall- 

 case 40, No. 45. 



Cellular Pyrites. Iron Pyrites (Mar- 

 casite) which has been deposited in thin 

 films between layers of Galena, on the re- 

 moval of which a honeycomb appearance 

 is produced. 



Locality. Johanngeorgenstadt, in Saxony. 



Cellular Quartz. A cellular variety 

 of Quartz, which is sometimes so porous as 

 to float in v>'ater till the air contained in its 

 pores escapes. (See Float Stone.) 



It is found in Cornwall, at Relistian mine, 

 Cardrew mine, Huel Alfred, Pednandrea, 

 &c. The curious brownish-grey variety 

 met with at Alston Moor, in Cumberland, 

 is probably the skeleton or the divisions of 

 Septaria vv^hich have been left after the re- 

 moval of the other portions of the stone. 



Cement Copper, A7r?^;an. Metallic Cop- 

 per, produced by the precipitation of copper 

 by iron, from w^aters which held it in 

 solution. 



Cendres Noires. Friable and pulveru- 

 lent Lignite, from alluvial beds, containing 

 a considerable quantit}' of Sperkise, or Iron 

 Pyrites, and used by the agriculturalists of 

 Picardy as a manure. 



After being burnt, either by spontaneous 

 combustion or calcination, it is called Cen- 

 dres rouges. 



Centralassite, H. How. A mineral oc- 

 curring between the external coating and the 

 central portion of a reniform nodule, partly 

 imbedded in crystalline trap. Structure 

 lamellar. Consists of plates radiating from 

 a centre, and forming truly spherical con- 

 creticms. Colour white, sometimes yellow- 

 ish. Translucent; perfectly transparent in 

 thin plates, which are easily obtained and 

 readily broken across. Lustre subresinous ; 

 highiv pearly on cleavage planes. H. 3-5. 

 S.G. 2-45 to 2-46. 



