70 CERIUM OXIDE SILICIFERE. 



Cerium Oxide Silicifere, HaHy. See 

 Cerite. 



Cerium Oxide Yttrifere, Beudant. 

 See Yttrocerite. 



Cerium Phosphate, Dufrenoy. See 

 Edwardsite. 



Cerolitk. See Kerolite. 



Ceroxydul-kohlensaures, Berzelius, 

 Rammehberg. See Lanthanite. 



Ceruse, Beudant. Cerusite, Haidinger. 

 Cerussit, V, KobelL. Cerussite, Brooke ^ 

 Miller. Rhombic: primary form a right 

 rhombic prism. It occurs in tabular crystals, 

 in six-sided prisms variously terminated, 

 and in other macled crystals of different 



Fig. 95. 



forms: also massive and compact, rarely 

 librous. Colour white, passing into grey and 

 greyish-black ; sometimes tinged green or 

 blue by some of the salts of Copper. Lustre 

 resinous on fractured surfaces, adamantine 

 on planes of cleavage. Transparent to trans- 

 lucent : when transparent, it is doubly re- 

 fractive in a high degree. Streak white. 

 Brittle: fracture commonlv small con- 

 choidal. II. 3 to SS. S.G. 6-4G to 6-iS. 



Fig. 9S. 



W" 



Comp. Monocarbonate of lead or Pb, C 

 = carbonic acid 16-42, oxide of lead 83-58. 



Analysis from Leadhills, by Klaprotli : 

 Carbonic acid . . . .16 



Oxygen 5 



Lead 77 



Water 2 



100 



BB decrepitates, becomes first red, then 

 yellow, and lastly melts into a globule of 

 metallic lead, the charcoal being covered 

 with yellow fumes. It dissolves readily and 

 with effervescence, in dilute nitric acid. Its 

 powder thrown on hot coals emits a phos- 

 phorescent light. 



Localities.— British. Leadhills in Lanark- 



CERVANTITE. 



shire, and Wanlock Head in Dumfriesshire 

 {fig. 95) : also in magnificent tabular crys- 

 tals at Logylas, near Aberystwith, in Cardi- 

 ganshire. Cornwall, in exceedingly delicate 

 snow-white acicular crystals, at Pentire 

 Glaze and St. Minver Consols. Derbyshire, 

 nrincipallv in mines in the neighbourhood 

 of Matlock {fig. 96) and Wirksworth. Cum- 

 berland, Devonshire, Durham, Shropshire, 

 Northumberland, Yorkshire, Westmoreland, 

 and at the Sark mine in the Channel Islands. 

 Ireland, in heart-shaped macles at Seven - 

 churches, Wicklow co. — Foreign. Very 

 beautiful crystals are found in the mining 

 districts of Saxony, especially at Johann- 

 georgenstadt ; Nertschinsk, and Beresof in 

 Siberia ; near Bonn on the Rhine, Clausthal 

 in the Harz ; Tarnowitz and Janowitz in 

 Silesia; Bleiberg in Carinthia ; Alsace 

 and Croix-aux- Mines (Vosges) in France; 

 the Crimea; Gazimour in Daouria, &c. 'in 

 the United States, at Phenixville, in Penn- 

 sylvani>a; Perkiomen lead mines, near 

 Philadelphia; Austin's Mines, Wythe co., 

 Virginia, and especially at King's Mine in 

 Davidson co., N. C. 



Brit. Mus., Case 49. 



31. P. G. Principal Floor, Wall-case 

 45, and Case 15 (British). Wall case 21 

 (Foreign). 



Next to Galena, Cerusite is the most 

 common ore of lead, but it does not occur so 

 abundantly or in such quantity as often to be 

 an object of consequence to the metallur- 

 gist. It may be distinguished from Barytes 

 by the blackening of its surface when 'ex- 

 posed to the vapour of sulphide of ammonia. 



Cervantite, occurs in acicular crystals ; 

 also massive, and as a crust or a powder. 

 Colour nearly white, Isabella-yellow, or 

 sulphur-yellow, with a greasy, bright or 

 earthy lustre. 



Comp. Sb + Sb = oxvgen 19-9, antimony 

 80-1-100. 



Analysis by Dufrenoy : 



Oxygen . . . 16-85 

 Antimony .... 67*50 

 Carbonate of lime . . 11-45 

 Peroxide of iron . . 1*50 

 Loss 2-70 



99-80 



BB infusible, but on charcoal easily re- 

 duced. 



Soluble in muriatic acid. 



Localities. Chazelles inAuvergne: Fel- 

 sobanya, and elsewhere in Hungar3\ 



Cervantite results from the alteration of 

 Grey Antimony (with which it is associated) 



