well
as from a personal examination of many of the localities where gems are
found. Its object is to present, in convenient form, as many of the
facts as possible regarding the precious stones peculiar to. the United
States, Canada, and Mexico, so that they may be available, not only to
the mineralogist, the miner, the mineral and gem collector, the
archaeologist and the jeweler, but also to the public, the conditions
under which they occur, the methods by which the mining and search for
them are conducted, the value and production of different stones, and
also an account of the collections in these countries.
A
brief general description of each important gem will be found at the
beginning of the article and a series of analyses indicating the
composition of each precious stone, from the latest or most reliable
authority, and for comparison a typical analysis is generally included.
Full reference to the literature of the subject is given in the
foot-notes.
The
chapter on Canadian precious stones is based on a report prepared for
" The Mining and Mineral Statistics of Canada" for 1887, and its use is
permitted through the courtesy of the authorities of the Canadian
Geological Survey. One chapter is devoted to pearls, with a full
account of their mention by the early explorers, their occurrence in
mounds, Indian graves, and similar remains ; another devoted to the
imports and values, and to the cutting of gem stones, with mention of
some remarkable gems owned in the United States, and a brief
description of the best known collections in this country.
A
number of minerals are enumerated that are not only below 7 in the
scale of hardness, but that are even below 6, and apparently too soft
for cut gems; yet cups, vases, and other objects may be made of these
stones, such as serpentine and catlinite, which could be successfully
used where transparent apatite could not, because they are opaque, do
not show scratches, and always present an even, good color.
During
recent years a number of items have appeared in the newspapers relative
to the finding of alleged valuable gems, which have proved on
investigation to be without foundation. As newspaper statements are
sometimes copied into special literature, it may be well to refer
briefly to them.
