NOME VIII. KOLLANITE. 



concentric zones of agate, while others are 

 spotted in infinite variety ; and others, though 

 rarely, are unicoloured. The beautiful marble 

 bricia of Aix seems of a similar instantaneous 

 formation, and approaches the nearest in point 

 of variety, but is far inferior in tints and polish. 

 Nor can a comparison be instituted with others 

 the most beautiful amongst the rocks ; such as 

 blue and green granite, serpentine, miagite, 

 niolite, corsilite, jasper, or even lazulite, which 

 only present a few colours, and little variety in 

 the texture ; while here the colours and variety 

 are infinite, and accompanied by the constant 

 discovery of minute beauties and accidents. 



As not only foreigners, but even our own 

 writers, seem strangers to the varieties of this 

 stone, it may be proper to specify a few. 



1. A Kollanite of grey pebbles in a grey ce- 

 ment, the pebbles being sometimes lighter, some- 

 times darker than the gluten, which is purely 

 siliceous, and of a more shining or unctuous 

 lustre than the nodules. This is the simplest 

 appearance of the substance, and never esteemed 

 worthy to be polished. 



2. Nodules of a blackish grey, with some of 

 transparent yellow, imbedded in a fawn-colour 

 cement ; consisting either of granular quartz, or 



