PART I.
Precious Stones: their
Origin; Geological Position; Physical Characteristics; Optical and
Electrical Properties; External Characteristics ; Susceptibility to the
action of Eight and Heat.
" The jewel that we see, ive stoop and raise; But that we do not see, we tread upon, And never think of it."
In the
following pages we intend to treat not merely of precious stones
strictly so called—that is, such mineral substances as have in all
times atÂtracted the attention of man by their hardness, their
brilliancy, their colour, their scarcity, &c, but also of a certain
number of productions which have nothing in common with the true
precious stones, either in composition or origin, but which as articles
of finery and adornment play precisely the same part as the latter.
When we contemplate the boundless wealth of
nature we might imagine that the number of precious
l
