388 SYSTEMATIC DESCRIPTION OF PRECIOUS STONES 



and in small masses. The majority of the stones which come into the market do not much 

 exceed lentils in size. 



Cacholong (Kascholong- (German), mother-of-pearl-opal, or mother-of-pearl-agate) 

 is an opal with very little translucency, a feeble lustre of the mother-of-pearl type, and 

 a milk-white, reddish, or yellowish colour. It breaks with a large conchoidal fracture 

 with very smooth surfaces. Like hydrophane, it is very porous and adheres to the tongue ; 

 but, unlike this, does not become transparent on immersion in water. It is fashioned into, 

 all kinds of small articles and fancy goods, and is sometimes cut en cabochon for gems, some 

 specimens when polished having quite a pretty appearance. In some cases the stone is. 

 built up of alternate light and dark bands of material, as in onyx, or it may be interbanded 

 with thin layers of bluish or greenish chalcedony, specimens of this description being 

 sometimes used for cameos. 



Fine specimens of good size are not very frequently met with, and consequently 

 command rather high prices. Cacholong is found in small amount at various localities,, 

 usually in thin layers 1 to 4 lines thick, these layers alternating with chalcedony. The 

 name is said to be derived from the Cach river in Bucharia, Central Asia, in which it, 

 occurs in the form of loose pebbles ; it has been also derived from the Tartar word, 

 kaschtschilon, meaning beautiful stone. The above-named river has long been mentioned! 

 in connection with the occurrence of cacholong, but nothing further about the locality is 

 known. The stone was formerly known to the inhabitants of the region as kalmuck-opal,, 

 or, as it was thought to be a kind of agate, as kalmuck-agate. It is also found in the 

 basalts of the Faroe Islands and of Iceland, and as reniform and botryoidal incrustations on 

 the limonite of Hiittenberg in Carinthia ; also on the shores of the Bay of Fundy in Nova 

 Scotia. The mineral, which at no time has had any great importance, occurs at all thes& 

 places in association with opal and chalcedony. 



