Home » categories » rare book library » Castellani. Gems.
This chapter is tagged (labeled) with: 

Idocrasium

Hauyna Page of 243 Hydrophane Text size:minus plus Restore normal size   Mail page  Print this page
128
GEMS.
America, the name of Vesuviana was changed to that of idocrasium, which is derived from eî8dos, form, and κράαsις, mixture, which is intended to signify the multi­tude of forms under which it is naturally found.
When transparent, and of a pure green or brown, it is used for rings and pins, and is principally worked in Naples and Turin.
It is cut on a leaden wheel, and receives polishing by means of the pumice-stone.
It is of little value, and is very little known to foreign traders.
The Neapolitan idocrasium is often called in minera­logy the Italian chrysolite ; it is, however, different from the true chrysolite, having much less specific gravity. It was even mistaken for green garnet, but the hard­ness of the latter is much greater.
XLIX.
HYDROPHANE.
This stone is a resinous quartz.
It is almost opaque, iridescent, and has the singular property of becoming transparent when dipped in water ; whence its name of vèwp, water, and φαίνω, to display, that is, transparent by means of the water.
It is either white or grey, sometimes greenish and sometimes yellowish. It is solid, rather soft and
Hauyna Page of 243 Hydrophane
Suggested Illustrations
Other Chapters you may find useful
Other Books on this topic
bullet Tag
This Page