EMERALD. 
399 
lieving that the true emerald ought to resist a blow 
with a hammer as well as the diamond. The beau- 
tiful deep green colour for which the emeralds of 
Peru are so eminently distinguished, is apt to vary 
considerably in different pieces, and sometimes, 
among a great number of crystals of this gem, not 
one will be found perfect. The principal defects 
are fissures which occasionally occur in the stone, 
and a want of that transparency and lustre which 
constitutes its chief beautv. 
J 
Emeralds are found in different situations in the 
earth ; sometimes they are met with in black lime- 
stone, sometimes grouped with crystals of quartz or 
felt-spar, and occasionally concealed in the cavities 
which are naturally formed in granit. A most 
beautiful group of these gems is to be seen at Lo- 
retto in the treasure of the holy chapel near An- 
cona; it is composed of about fifty hexagonal prisms 
of emerald of an inch in diameter and two inches 
long, crystallized on a basis of white quartz mixed 
with mica. There is at present, in the Museum 
d’ Histoire Naturelle , an emerald cut in the shape 
of a dome, which formerly decorated the crown of 
Julius the Second. It is of a dull green colour, 
about two inches high, and an inch and a half in 
diameter. This must have been a native of the old 
continent, since America was hardly discovered when 
Jul ius the second was advanced to the pontificate. 
Although Peru is famous for producing the finest 
emeralds, they are not confined to that country ; 
but are likewise produced in other parts of the 
