326 RUBY SILVER. 



brought to the form and size required, 

 anotlier stone of fine grain is required." 



The last process is performed by rubbing 

 the Ruby on a pLate of copper or brass, 

 until it is thoroughly polished, when the 

 gem is ready for market. 



Rubies are imitated by Spinel, Garnet, 

 Hyacinth, red Quartz, calcined Amethyst, 

 red burnt Brazilian Topaz, and by red 

 Tourmaline. 



The Ruby has been valued as a gem from 

 the earliest times of which we have any re- 

 cord. The Sardius, mentioned in Exod. 

 xxviii. 17, and supposed to mean the Ruby, 

 held the first place amongst the twelve stones 

 which were ordered to be placed on the 

 ephod of the Jewish high-priest, and was 

 engraved with the name of Reuben. 



In Proverbs iii. 13, 15, Solomon says, 

 " Happy is the man that findeth wisdom 

 .... She is more precious than rubies, and 

 all the things thou canst desire are not to 

 he compared unto her."' See also Job 

 xxviii, 18. Prov. viii. 11; xx. 15; xxxi. 

 10. Lam. iv. 7. 

 Brit. Mus., Case 19. 



M.P.G. Horse -shoe Case, Nos. 786, 

 787, 797—804. 



Ruby Silver. See Pyrargyrite. 

 Ruby Sulphur, Jameson. See Real- 

 gar. 



Ruddle. See Reddle. 

 Ruin Agate. See Brecciated Agate. 

 Ruin Marble. See Cotiiam Marble. 

 Ruthekfordite, C. U. Skepard. Ob- 

 lique. No cleavage. Occurs in crj^stals and 

 grains. Iron-black external!}^ and not at 

 first sight distinguishable from Samarskite. 

 Colour of fresh surface, blackish- or yel- 

 lowish-brown. Earthy. Opaque or trans- 

 lucent in thin fragments, and transmitting 

 a smoky orange-brown light. Lustre vitreo- 

 resinous, shining. Yields to the knife with 

 difficulty. Streak yellowish - brown, ap- 

 proaching to fawn-colour. Very brittle. 

 Fracture perfectly conchoidal. H. 5*5. S.G. 

 5-5. 



Comp. Titanic acid and lime. 

 BB alone infusible ; with borax forms 

 slowly a clear yellow glass. 



Exposed to heat in a glass tube, it de- 

 crepitates slightly, and gives off a little 

 water ; the mineral on cooling is dark yel- 

 lowish-brown, with a resinous adamantine 

 lustre, in appearance resembling some varie- 

 ties of Blende. Decomposed by prolonged 

 boiling with concentrated sulphuric acid, 

 and is then completely soluble in a very 

 large volume of warm water. 



RUTHILE. 



Localitv. The gold-washings of Ruther- 

 ford co.. North Carolina; with Samarskite, 

 Rutile, Brookite, Zircon, and Monazite. 



Rutherfordite is easily distinguished from 

 Samarskite, which it otherwise closely re- 

 sembles, by the streak and by its trans- 

 lucency. 



RUTHILE, Brochant. RuTiL, Weryier. 

 Rutile, Dana, Nicol, Phillips. Pyramidal. 

 Occurs in four- or eight-sided prisms, ter- 

 minated by pyramids, either single or geni- 

 culated, and often striated longitudinally : 

 also in reticulated masses formed by acicular 

 and capillary macled crystals : also massive 

 and imbedded. Structure lamellar. Colour 

 usually reddish - brown and opaque; or 

 blood-red and translucent or transparent: 

 sometimes yellowish or black. Lustre metal- 

 lic-adamantine. Streak very pale brown. 

 Brittle. Fracture imperfect-conchoidal or 

 uneven. Acquires negative electricity by 

 friction. H. 6 to iJb. S.G. 4-18 to 4-25. 



Fig 368. 



Comp. Binoxide of titanium or titanic 



acid, Ti = titanium 60-98, oxygen 39-02 = 

 100. 



Analysis, from St. Yrieix, by H. Rose : 

 Titanic acid . . . . 98*5 

 Peroxide of iron . . . 1-5 



100-0 

 BB alone infusible, with borax yields a 

 transparent reddish -yellow glass in the 

 outer flame, which assumes a dirty violet- 

 colour in the inner flame. 



Localities Scotch. Glen Finnart, Ar- 



gyleshire. Perthshire. Crianlarich, in large 

 striated prisms and in fibrous masses; Craig 

 Cailleach, near Killin, Fifeshire. Hills- 

 wick, Shetlands. — Irish. Co. Donegal; 

 near Dunfanaghy, and at Malin Beg, in 

 white crj^stalline Quartz. — Foreign. St. 

 Yrieix, near Limoges, in France, and in 

 Castile, in geniculated twin crystals, which 

 are often of large size. The Alps. St, 

 Gotthard, in Switzerland, reticulated on 

 crystals of Specular Iron. Rosenau, in Hun- 

 gary. Brazil, in acicular crystals imbedded 

 in "limpid Quartz, which, when polished, 

 exhibits hair-like crj'stals of Rutile, of a 

 blood-red colour by transmitted light: 

 {Venus' Hair-stone.) Ohlapian, in Tran- 



