LXV.
NATROLITE.
This mineral has been but recently discovered.
It received its name from the Latin natrum, which means soda, because that alkali is its principal component.
It
has a rough breakage, is translucent at the edges, and of a pearly or
white light ; sometimes deep red or yellow, and often in alternate
zones.
It scratches glass with difficulty, but can be marked by felspar. It produces a white powder ; has a specific gravity of 2Ί6 ; melts
under the action of the blowpipe, into a spongy, colourless glass; is
composed of soda, alumina, silex and water; sometimes a small quantity
of oxide of iron is mixed with it.
Natrolite is found in Switzerland, Bohemia, Saxony, Scotland, and Nova Scotia.
Natrolite,
on account of the polish which it takes, has been used in jewellery,
but it was not satisfactory, and now nothing is thought of this gem, so
that it has no value in commerce.
LXVI.
NEPHRITE. See jade.
