CHIASTOLITE. 

 Chiastolite, Phillips. Rhombic. A 

 variety of Andalusite, occurring cr3-stal]ized 

 in -uiute or grey right rhombic prisms, 

 which present a black or bluish-black cross 

 in their transverse section. Lustre vitre- 

 ous. Translucent. Streak white. Frac- 

 ture splinterv. H. 3 to 7-5. S.G, 2-94 to 

 3-09. 



Fig. 109. 



Camp. Anhydrous silicate of alumina, or 



Al b'i = alumina 63, silica 37 = 100. 



Avalysis from Lancaster, by Bunsen : 



Alumina .... 58-56 



Silica 39-09 



Peroxide of manganese . 0-53 



Lime 0-21 



Loss by ignition . . . 0-99 



99-38 



BB alone infusible, with borax difficultly 

 fusible, forming a clear glass, and with still 

 greater difficulty and less perfectly in mi- 

 crocosmic salt. 



Localities. — English. Cumberland, at the 

 top of Skiddaw, and at Carrock Fells, in 

 Slate ; Saddleback ; Dacre Castle, near Ulls- 

 water. Devonshire ; Ivy Bridge, and near 

 Okehampton. Fig. 109. — Irish. Agnavanagh 

 in Wicklow; in mica-slate, near Killiney 

 Bay; Baltinglass Hill, on the borders of 

 Carlow. — Foreign. Near Bareges in the 

 Pyrenees ; St. Jago de Compostellain Spain ; 

 near Santa Elena in the Sierra Morena ; 

 St. Brieux in Basse Bretagne ; abundantly 

 in the townships of Lancaster and Sterling, 

 Massachusetts, U.S. 



Name. From ^fa-rro?, decussated. The 

 name Chiastolite was given by Karsten, on 

 account of the resemblance of the dark lines 

 on the summits of the crystals to the Greek 

 letter X' 



Brit. Mus., Case 26. 



31. P. G. Horse-shoe Case, No. 1005. 



Childrenitk, Levy, Greg §• Lettsnm. 

 Rhombic. Primary form a right rhombic 

 prism. Occurs in yellow or brownish-yel- 

 low cr^^stals or crystalline coats on Siderite, 

 Pyrites or Quartz. Lustre vitreous inclin- 

 ing to resinous. Translucent. Streak paler 

 than the colour. Fracture uneven. H. 4*5 

 too. S.G. 3-2. 



CHILEITE. 77 



Fig. 110. Fig. 111. 



Comp. (R3, Al)5 P3+ 15H, or 2(Fe, Mn)4 



P + a\P + 1oH. 



Analysis bv BamraelsheTg ; 



Phosphoric acid . . . 28-92 

 Alumina .... 1444 

 Protoxide of iron . . . 30-68 

 Protoxide of manganese . 9-07 

 Magnesia .... 0'14 

 Water 16-98 



100-28 

 BB colours the flame bluish-green ; with 

 the fluxes affords reaction of iron and man- 

 ganese. 



Localities. This mineral is nearly a Cor- 

 nish species: it has been found at Crinnis 

 Mine near St. Austell, and at the George 

 and Charlotte Mine, and in the vicinity of 

 Tavistock, at Huel Crebor. 



Name. It was first distinguished by 

 Levy, by whom it was named after Mr. 

 Children of the British Museum. 

 Brit. Mus., Case 57. 

 M. P. G. Horse-shoe Case, No. 1125. 

 Childrenite may be distinguished from 

 Siderite by the superior hardness and lustre 

 of its crystals. 



Chileit. The name given by Breithaupt 

 to a variety of Gothite from Chile. 

 Analysis by Breithaupt : 



Peroxide of iron . . . 83-5 

 Oxide of copper . . .1-9 



Silica 4-3 



Water 10-3 



100-0 

 Chileite. The name proposed by Ken- 

 gott for a Vanadate of Lead and Copper de- 

 scribed by Domeyko, and worked for Cop- 

 per and Silver at the Silver mine, Mina 

 Grande, or Mina de la Marqueza, in Chili, 



