62 OCHOA STONE. 
Agates are used in several kinds of ornamental work, 
and particularly for necklaces and seals. They are 
occasionally made into cups, the handles of knives and 
forks, hilts of swords and hangers, and the tops and 
bottoms of snuff-boxes. The less ornamental kinds are 
manufactured into small mortars, which are employed 
by enamellers and others, for pounding such substances 
as are too hard to be reduced in any other way. They 
are also made into instruments for grinding colours, 
and into polishers for the glazing of linen. In the 
Electoral Cabinet at Dresden, and the Ducal Cabinet 
in Brunswick, there are several elegant vases formed of 
agate. 
The most beautiful agates which our island produces 
are known by the name of Scots Pebbles. These are 
found in various parts of Scotland, but principally on 
the sea-shore, in the neighbourhood of Dunbar. Agate 
pebbles are found on several of the English shores, as 
those of Suffolk, Dorset, Scotland, Wales, and Ireland; 
and sometimes even in gravel pits. Many of them will 
bear cutting and polishing as well as the best agates of 
foreign countries. 
Agates are occasionally seen to be figured in very 
singular manner ; but this, in some instances at least, is 
suspected to be the work of art. One is mentioned in 
the church of St. Mark, at Venice, which had the re- 
presentation of a king's head surmounted by a diadem. 
On another, was represented a man in the attitude of 
running. But the most remarkable of all seems 
to have been one which contained a representation of 
the nine Muses, with Apollo in the midst of them ! 
It must be remarked that agate is not, as some mine- 
ralogists imagine, a simple mineral, but that it is com- 
posed of various species of the quartz family, intimately 
blended together. It consists chiefly of calcedony (91 ), 
with flint, hornstone, carnelian (93), jasper (96), cacho- 
long (105), amethyst (79), and quartz (76). Of these 
minerals sometimes only two, and sometimes three or 
more, occur in the same agate. Its varieties, conse- 
quently, are extremely numerous. 
