rely different class to the minerals of a metallic nature. These
particular and non-metallic minerals, therefore, because of their
comparative rarity, rise pre-eminently above other minerals, and become
actually "precious."

This is, at the same time, but a comparative term, for it will readily
be understood that in the case of a sudden flooding of the market with
one class of stone, even if it should be one hitherto rare and
precious, there would be an equally sudden drop in the intrinsic value
of the jewel to such an extent as perhaps to wipe it out of the category
of precious stones. For instance, rubies were discovered long before
diamonds; then when diamonds were found these were considered much more
valuable till their abundance made them common, and they became of
little account. Rubies again asserted their position as chief of all
precious stones in value, and in many biblical references rubies are
quoted as being the symbol of the very acme of wealth, such as in
Proverbs, chapter iii., verses 13 and 15, where there are the passages,
"happy is the man that findeth wisdom ... she is more precious than
rubies"--and this, notwithstanding the enormous quantity of them at that
time obtained from the ruby mines of Ophir and Nubia, which were then
the chief sources of wealth.

It will also be remembered that Josephus relates how, at the fall of
Jerusalem, the spoil of gold was so great that Syria was inundated with
it, and the value of gold there quickly dropped to one-half; other
historians, also, speaking of this time, record such a glut of gold,
silver, and jewels in Syria, as made them of little value, which state
continued for some considerable period, till the untold wealth became
ruthlessly and wastefully scattered, when the normal values slowly
reasserted themselves.

Amongst so many varieties of these precious minerals, it cannot be
otherwise than that there should be important differences in their
various characteristics, though for a stone to have the slightest claim
to be classed as "precious" it must conform to several at least of the
following requirements:--It must withstand the action of light without
deterioration of its beauty, lustre, or substance, and it must be of
sufficient hardness to retain its form, purity and lustre under the
actions of warmth, reasonable wear, and the dust which falls upon it
during use; it must not be subject to chemical change, decomposition,
disintegration, or other alt