The
fact that there is no standard classification of precious stones is
curiously illustrated by the great variation exhibited by leading
authorities on the subject. Mr. Edwin W. Streeter, the famous English
author of books on precious stones, after discussing the various
factors of value in several precious stones, writes in the first
chapter of his book Precious Stones and Gems, as follows:
It
is difficult to arrange the various Precious Stones in the order of
their relative value, that order being subject to occasional variation
according to the caprice of fashion or the rarity of the stones.
Nevertheless it is believed that the following scheme, in which all
Precious Stones are grouped in five classes, fairly indicates the
relative rank which they take at the present day.
