INGENUITY AND LUXURY 



minute quantity of oxide of chromium. Fine emeralds 

 are frequently alluded to as "Spanish emeralds," giving 

 the natural impression that Spain was the source of these 

 very fine gems. In point of fact there are no emerald 

 mines in the Spanish peninsula, and there never have 

 been. But there were great quantities of emeralds 

 kept as ornamental trinkets by the natives of Peru 

 at the time of the Spanish conquest, and like almost 

 everything else of value there, they soon found their 

 way into the hands of the Spanish nobility. For many 

 years, therefore, the finest specimens of emeralds were 

 in Spain, and hence the term "Spanish emerald" was 

 a presumptive guarantee of fine quality. 



Emeralds have always been found in Africa, and there 

 were Egyptian mines many centuries before the Chris- 

 tian era. Asia, North America, and Australia also 

 produce the gems in small quantities. But the princi- 

 pal source is still the South American continent, 

 Colombia and Peru being the centers of supply. The 

 mines of Muzo and Coscuez in Colombia, discovered 

 about 1550, still supply the world with the greatest 

 quantity, and finest quality, of emeralds. They are 

 found in limestone and slate, occurring in lodes or 

 as isolated crystals. 



A somewhat less important group of gems, whose 

 range of colors equals the corundum gems, are those of 

 the mineral spinel. They are not as brilliant stones 

 as the corundum or beryl group, but the finest speci- 

 mens are sometimes only slightly inferior. In proof 

 of this is the fact that the "Black Prince's ruby" in 

 the crown jewels of Great Britain, which was until 



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