DOMAIN IV. TALCOUS, 



MODE X. GREEN MARBLE. 



In most rocks the green colour betrays the 

 presence of magnesia, whence it becomes an 

 emphatic epithet. In the magnesian limestone 

 this effect is not observable, because the minute 

 talcous particles are intimately combined with 

 the calcareous ; but where they are aggregated 

 apart, as in the green granitel and green marble, 

 the colour becomes characteristic. The latter 

 is also called sometimes serpentine marble, be- 

 cause in fact the green parts belong to the rock 

 called serpentine, while the white are purely 

 calcareous. These marbles have never been 

 classed with glutenites, being neither bricias nor 

 pudding-stones, but an irregular and original 

 compound of serpentine and marble, in which 

 the former is preponderant. 



The most celebrated rock of this description 

 is that called the verde-antico, or ancient green, 

 in which a green serpentine with dark spots, 

 seemingly rather argillaceous, is interspersed 

 with a pure white marble. This is the Laconian 

 marble of the ancients, of which there were 

 quarries near Mount Taygetus; and Pliny has 

 rightly characterised it as more cheerful than, 



