KNoWI.l.DCl-: 





1 IGLKL /. 



The " geiiiining " basket in use. 



possesses a similarly extensive range of colour, except 

 that vellow i? missing, is the spinel. Some specimens 

 of this, somewhat resemhle rubies and sapphires, and 

 are therefore often described as " spinel rubies," and 

 "spinel sapphires" respectively. It is, however, 

 verv much softer than corundum, and is one of the 

 three gem-stones, occurring in the form of crystals, 

 which are singly refractive, the other two being 

 diamond and garnet. 



There is a remarkable Hame-red variety of spinel, 

 the colour of which is unique in the whole mineral 

 world, not even excepting the ruby. It is an 

 exquisite gem of great value. 



The chrvsoberyl is an attractive gem stone. 

 although its heautv is somewhat unappreciated. It 

 occurs in shades of Autumn green, brown, and 

 vellow, and possesses great brillianc\-. There are, 

 however, two varieties of this gem-mineral which 



form well-known and valuable [jrecious stones : of 

 these, the most important is known as the alexan- 

 drite. (See Figure 4.) Fine examples of this gem 

 by daylight appear pistachio-green, changing to rich 

 mulberry-red by artificial light. 



Cevlon is the chief source of alexandrites, 

 although a few are found in Siberia. 



The other important variety of chrysoberyl is the 

 cyniophaiie or cat's-eye, which, when cut with a 

 smooth convex face presents a narrow white line 

 glittering across it, which has a fancied resemblance 

 to the iris of a cat. The position of the line or rav 

 alters as light strikes it from different angles, giving a 

 [x'culiarly mysterious effect. Cymophanes are only 

 found in Ceylon. 



The rarest and most curious of all precious stones 

 are those cat's-eyes w hich change from green to red, 

 as do the alexandrites. 



The basket is handled with a eircular movement. 



riic hyhler stones shp over the edge of the basket. 



