EADIOLITE. 

 Radiolite. a variety of Natrolite, from 

 Brevig, in Korway. 



Analysis, by Scheerer : 





Silica . . . . 



. 48-38 



Alumina 



. 26-42 



Peroxide of iron . 



. 0-24 



Soda . . . . 



. 13-87 



Potash 



. 1-54 



Lime . . . . 



. 0-44 



Water . . . . 



. 9-42 



100-31 



Rainbow Chalcedony. Chalcedony 

 consisting of thin concentric layers, which 

 ■when cut across and held towards the 

 light displays an iridescence, more espe- 

 ciall}' if the stone is cut in thin slices. 



Rammelsbekgite, Haidinger. See Chlo- 

 anthixe, or Tesseral White Nickel. 



Rammelsbekgite, Breithaupt, Dana. An 

 arsenide of*-Nickel, with the same composi- 

 tion as Chloanthite, or Ni As2:=^ Nickel 28-3, 

 arsenic 71-7 = 100. Tn appeai-ance and 

 physical characters it resembles Marcasite, 

 orXVhite Iron Pyrites, but differs from • it, 

 according to Dana, in being slightly ductile. 

 H. 5-25 to 5-75. S.G. 7 to 7-19. 



Localities. Schneeberg in Saxon3', and 

 Riechelsdorf in Hesse. 



Name. Named by Breithaupt after the 

 chemist, C. F. Rammelsberg, of Berlin. 



Brit. jMus., Case 4. 



Rakcierite, Leymerie. A variety of 

 Hausmannite,. resembling Pyrolusite, and 

 like it giving off chlorine when treated Avith 

 muriatic acid. Occurs in earthy masses of 

 a deep brown colour. Soils the lingers. 

 Streak chocolate- brown. 



Analysis, from Groroi (Mayenne), by 

 Berthier : 



Oxygen .... 26-79 

 Manganese . ► . . 48-41 



Water lo-80 



Ferruginous clay . . 9-00 



100-00 

 Rancierite Argentine, or Rancie- 

 RITE Metalloide, The purest and, in the 

 absence of crystals, the t}'pical form of the 

 above mineral. Found in small spongy, 

 prismatic, or filamentary masses, or in beds, 

 with a metallic aspect, and a silvery colour, 

 sometimes tinged with violet, in cavities of 

 massive Linionite or Brown Hematite. Very 

 soft and light. 

 Localities. The mountain Rancie or 



RAPHTLITE.' 313 



Rancier (Ariege). In the mines of the 

 same kind around Le Canigou, in the valley 

 of Baigorry. Also in the Dept. of Isere, and 

 at Saint-Jean de Gardonnenque, in the 

 Cevennes. 



Randanite, Salvetat. A soluble silica, 

 principally composed of infusorial remains. 

 It occurs as a fine earth, or in compact 

 earthy masses near Algiers, and in France 

 at Ceysbat, near Randan (whence the name 

 Randanite), in the Puy-de-D6me. 

 Analysis, from Cevssat, by Fournet ; 

 Soluble silica " . . .87-20 

 Alumina and peroxide of iron 2-00 

 Sand . . . . . 0-80 

 Water, carbonic acid, and or- 

 ganic matter . . . 10-00 



100-00 



Raphanosmite. The name given by 

 Von Kobell to varieties of Clausthalite, in 

 which a part of the lead is replaced by 

 copper. By Brooke & Miller they are com- 

 prised under the term Zorgite. Found in 

 small fragments of a lead-grey and violet 

 colour, or of a perfect violet colour when 

 newly broken. Very soft and slightly 

 malleable. H. 2-5 to 3. S.G. 5-6. 

 Comp. Pb Se + Cu Se. 

 Analysis, from Tilkerode, in the Harz, 

 by H. Rose : 



Selenium .... 34-26 



Lead 47-43 



Copper .... 15-45 



Silver 1-29 



Lead and peroxide of iron . 2-08 



100-51 

 Raphilite, Thomson. A variety of As- 

 bestiform Tremolite, occurring in groups of 

 delicate acicular crystals (whence the name, 

 from p«<P'V, a needle). Colour Avhite or bluish - 

 green. Translucent. Lustre vitreous or 

 resinous. H. 3-5. S.G. 2-85. 



Comp. Ca Si + Mg5 Si2=silica 60-7, mag- 

 nesia 26-8, lime 12-5 = 100. 

 Analysis, bv T. S. Hunt : 



Silica . ' . . . . 55-30 



Alumina .... 0-40 



Magnesia .... 22-50 



Lime 13-36 • 



Protoxide of iron . , . 6-30 



Protoxide of manganese . trace 



Soda 0-80 



Potash .... 0-25 



Loss by ignition . . . 0-30 



99-31 



