78 SERPENTINE. EUPHODITE OR SAUSSURITE. 



des : it is not uncommon in the United States of North America. 

 In the Alps, it is observed that the rocks of serpentine lie principally 

 on that side which faces Italy, and the coast of Genoa. There is a 

 soft kind of serpentine, sufficiently tenacious to be turned in a lathe 

 into vessels of any shape, which resist the action of fire : hence they 

 are used for culinary and other purposes in some parts of Switzer- 

 land, in Lombardy, and even in Higher Egypt. The use of this 

 stone is of great antiquity, being distinctly mentioned by Pliny ; it is 

 called lapis oUaris, or potstone. 



In Cornwall, serpentine occurs with a micaceous rock lying over 

 granite, and forms part of the promontory called the Lizard point. 

 It occurs also near Liskeard, in the same county. It is not met with 

 in any other part of England that I know of; but I have observed 

 rocks approaching the nature of serpentine in Charnwood Forest, 

 and in the county of Radnor, in Wales. 



Beautiful varieties of red and green serpentine occur in the Isle of 

 Anglesea, about six miles from the Paris copper-mine. It is found 

 in beds of great thickness, associated with the common slate-rocks of 

 the district, which approach in their nature to talcous slate : asbestus 

 lies in considerable quantities in the partings between the beds of 

 serpentine. 



Some of the specimens of this serpentine have the characters of 

 the precious or noble serpentine ; the colours are principally dark 

 green, intermixed with spots and clouds of lighter green, and shining 

 laminae of schiller spar, or crystallized serpentine. The fracture is 

 conchoidal, and it is translucent at the edges. It resists the point of 

 a copper or brass tool, and breaks with great difficulty. Some varie- 

 ties contain crystalline limestone, but in smaller patches than in the 

 Italian verde-anlique ; occasional stripes and spots of steatite, asbest, 

 and quartz, occur in it. The red is sometimes intermixed with a 

 great variety of other rich colours in the same stone, as black, white, 

 greenish white, and dark green. It may be considered as a valuable 

 stone for purposes of ornamental architecture, for in beauty and du- 

 rability it is not exceeded by the costly marbles of Greece or Italy. 



By a mixture of serpentine v/ith talc or steatite, serpendne be- 

 comes soft and seclile, and forms the mineral called potstone, before 

 mentioned. A different combination of crystallized serpentine {dial- 

 lage) with jade, or felspar, forms one of the hardest and heaviest of 

 known rocks. It was first noticed by Saussure in rounded pieces 

 and loose blocks, scattered over several parts of the valley, near the 

 Lake of Geneva : to this mineral the name of Saussurite has been 

 given. It is much harder than quartz, and its specific gravity is 3*35 : 

 it is the hardest and heaviest of known rocks, composed only of 

 earthy minerals : the colour is, generally, greenish. Some varie- 

 ties of saussurite, as well as of serpentine, by exposure to the action 

 of water, acquire an external polish, like a coat of varnish : this may 

 be observed in the pebbles of bright green saussurite near Mont St. 



