308 DESCRIPTIONS OF MINERALS. 



lowish-green, brownish-yellow and brownish-red. Occurs 

 also fibrous and lamellar. The -lamellar varieties consist of 

 thin folia, sometimes separable, but brittle ; colors green- 

 ish-white, and light to dark green. Often in crystals pseu- 

 domorphous after chrysolite, chondrodite, and some other 

 minerals. 



Lustre weak ; resinous, inclining to greasy. Finer varie- 

 ties translucent; also opaque. H. =2*5-4. G. =2*5-2 '6. 

 Feel sometimes a little unctuous. Tough. Fracture con- 

 choidal. 



Composition. A hydrous silicate of magnesium, like talc, 

 but containing much more water and much less silica. 

 H 2 Mg 3 O s Si 2 + l aq-= Silica 43*48, magnesia 43*48, water 

 13*04 = 100. B.B. fuses with much difficulty on thin edges. 

 Yields water in the closed tube. Decomposed by hydro- 

 chloric acid, leaving a residue of silica. In some kinds the 

 Mg is replaced partly by Fe. 



Specimens of a rich oil-green color, and translucent, 

 bi caking with a splintery fracture, are sometimes called 

 precious serpentine, and the opaque kind, common serpen- 

 tine. 



Fibrous serpentine with a silky lustre is called Chrysotile, 

 and also Amianthus. Unlike asbestus, which it resembles, 

 it affords much w r ater in a closed tube. Metaxite, Picro- 

 lite, and Baltimorite are coarse fibrous kinds. A foliated 

 variety, from Hoboken, X. J., was named Marmolite, be- 

 fore it was known to be serpentine. Antigorite is a foli- 

 ated variety. Williamsite is similar. Rcfclanshite contains 

 nickel. 



A porcelain-like serpentine — the Meerschaum of Taberg 

 and Sala — has been called Porcellophite j and a resin-like 

 variety, Retinalite and Yorliauserite. 



Diff. The distinguishing characters are feeble lustre, 

 somewhat resinous, compact structure, little hardness, being 

 so soft as to be easily cut with a knife, and specific gravity 

 not over 2*6. 



Obs. Serpentine occurs as a rock, and the several varie- 

 ties mentioned either constitute the rock or occur in it. 

 Occasionally it is disseminated through granular limestone, 

 giving the latter a clouded green color : this is the verd an- 

 tique marble, called also Ophiohjte. 



Serpentine occurs in Cornwall ; near Portsoy in Aber- 

 deenshire, in Corsica, Siberia, Saxony, Norway at Snarum. 



