Precious stones have played an interesting part in the history of mankind. We may
suppose that upon the first development of a desire for ornamentation, the savage was attracted
by bright colored minerals found in the beds of streams, and, with advancing discrimination,
was pleased by pebbles presenting shades of yellow and red. It is a matter admitting of Uttle
doubt that the rolled alluvial gems were sought long before the first attempts were made to
obtain the less evident and more inaccessible minerals hidden in the rocks. It is likely that
some primitive digging was engaged in before means were devised for boring the stream peb-
bles, yet strings of bright stream stones probably formed the earhest jewelry that pleased the

1 To appreciate fully the bearing of the color of turquois upon its use, especially among primitive peoples, it is necessary to examine certain
recently advanced ideas regarding the significance of fundamental colors, of which the turquois is represented by two, green and blue. It has been
found by Prof. Victor Goldschmidt of Heidelberg that the spectrum colors, yellow, red, green, and blue, when arranged in a descending series
according t» their wave-lengths, and reduced to their simplest numerical expression, yield a series of harmonic numbers

N3=0 i . 1 2 3 00

red yellow green blue
in which the figures indicate the relative complexity of each color. The relations brought out in this series are in accord with a fundamental law,
known as the law of corn-plication, which was formulated by Goldschmidt from extended observations on crystal forms and later applied to the
theory of music and of colors.
