324 RUBACE. 



a disagreeable odour when rubbed. Meagre 



to the touch. 



Avalysis, by Richard Phillips : 



Alumina . . . . . 8<> 



Silica 4 



Carbon 10 



100 



Localities. Near Ashford and Bakewell, 

 in Derbyshire. South Wales, in Caermar- 

 thenshire and Breconshire. Albanj', near 

 New Zork, U. S. 



Rotten- stone is nearly peculiar to this 

 country, and is supposed'^to be derived from 

 the decomposition of shale or siliceous lime- 

 stone. 



RuBACE, or RuBASSE. Names given by 

 French lapidaries and jewellers to a variety 

 of Rock Crystal with rose-coloured cracks. 

 These fissures, which characterise the stone as 

 well as their colour, are artiticially produced 

 bv heating the crystal red-hot, and then 

 plunging it into a solution of purple of 

 cassius or carmine. By these means it is 

 made full of cracks, which become filled with 

 the colouring matter. The great difficulty 

 to be surmounted in the process is, that 

 the stone should only be cracked in the 

 interior, allowing a free passage to the 

 colouring liquid from the outside, which it 

 is difficult to understand. 



The French jewellers also apply the name 

 to cut and polished Quartz, slightly tinged 

 with violet, and besprinkled internally with 

 minute brown spangles of Specular Iron, 

 which reflect a bright red light, equal to 

 that of the most brilliant Ruby. These 

 stones are very rare. They are brought 

 from Brazil, but inferior kinds are found in 

 the iron mines of Nassau Ussing. 



RuBELLAN, Breithaupt. Probabh^ an 

 altered Biotite, occurs in small, reddish- 

 brown, hexagonal tables, which are not 

 flexible. Exfoliates in the flame of a can- 

 dle. H. less than 3. S.G. 2-5 to 2-7. 



Analysis, by Klaproth : 



Silica . . . « . 45 



Alumina 10 



Oxide of iron . . . - 20 



Lime 10 



Soda and potash . . . 10 

 Volatile matter ... 5 



100 

 Localities. With Mica and Augite at 



Schima, in Bohemia; and also in Saxony. 

 Brit. Mas., Case 32. 

 RuBELLiTE, Kirwan. Red Tourmaline, 



containing a considerable proportion of 



RUBY. 



manganese. It generally occurs in closely 

 aggregated crystals, varying in colour from 

 a slight tinge of red to a fine pink. 



Analysis, from Sarapulsk, by Hermann : 



Silica 39-70 



Alumina .... 40-29 

 Peroxide of manganese . 2-30 

 Boracic acid . . . 6'65 

 Lithia ..... 3-02 

 Magnesia . . . .0-16 

 Soda 7-88 



100-00 



BB alone on charcoal, turns milk-white, 

 intumesces, splits, and vitrifies at the edges, 

 but does not fuse: on platinum, with soda, 

 exhibits in the outer flame the bluish-green 

 colour indicative of manganese. 



L^ocalities. — Irish. Ox Mountain, near 

 Sligo ; of a red and green colour. — Foreign. 

 Near Katherinenburg and Sarapulsk, near 

 Mursinsk, in Siberia. Elba. Rozena, in 

 Moravia. Very fine specimens have been 

 found at Paris, Maine, U. S. : "some crys- 

 tals over an inch in diameter, transparent, 

 ruby-red within, surrounded by green, or 

 red at one extremity, and green at the 

 other.." {Dana.) " Some of the Siberian 

 specimens exhibit internally a brown or 

 blue colour, surrounded with carmine-red, 

 or some other lighter tinge, or internally a 

 red hue bordered with pistachio-green." 

 ( W. Phillips.) 



A specimen of uncommon form and di- 

 mensions, which was presented by the King 

 of Ava to the late Colonel Symes, when, 

 ambassador to that country, and afterwards 

 presented to the British Museum by the 

 Hon. Mr. Greville, is stated by Jameson 

 to have been valued at £1000. 



Brit. Mus., Case 40. 



RuBicELLE. The name given to yellow 

 or orange red varieties of Spinel. 



RuBiE EToiLE. Star Ruby. See Asteeia. 



Rubin. See Ruby. 



Rubinblende, Hausmann. See Peoust- 



ITE. 



Rubine d' Arsenic, Von Born. See Re- 

 algar. 



Rubinglimmer, Hausmann. A variety 

 of Gothite, occurring in foliated crystalliza- 

 tions of a hyacinth-red colour, with Brown 

 Hematite, at Eiserfeld, in the country of 

 Nassau; and in the Hollerter Zug, in the 

 Westerwald, in veins of Limonite. It is 

 also met with in translucent scales at Kil- 

 patrick in Dumbartonshire, with Zeolite. 



Rubis de Bohemb. Rose Quartz. 



Ruby. Under the general term Ruby 



