tle, and should be treated
accordingly. Here, however, we are dealing with a much less expensive
material than emerald, and if a customer desires a tourmaline in a ring
mounting, while it will be best to suggest care in wearing it, the
loss, in case of breakage, will usually be slight.

Kunzite, like all spodumene, has a pronounced cleavage. It should
therefore be used in brooches, pendants, and such jewels, rather than in
rings. Lapidaries dislike to cut it under some conditions because of its
fragility.

QUARTZ GEMS. Coming down to hardness 7 we have the various quartz gems
and jade (variety jadeite). The principal quartz gems are, of course,
amethyst and citrine quartz (the stone that is almost universally called
topaz in the trade). As crystalline quartz is fairly tough and lacks any
pronounced cleavage, and as it is as hard as anything it is likely to
meet with in use, it is a durable stone in rings or in other mountings.
In the course of time the sharp edges will wear dull from friction with
objects carrying common dust, which is largely composed of powdered
quartz itself, and which therefore gradually dulls a quartz gem. Old
amethysts or "topazes" that have been long in use in rings show this
dulling. There is, however, little danger of fracture with amethyst or
"topaz" unless the blow is severe and then any stone might yield.

The many semi-precious stones which have a quartz basis (such as the
varieties of waxy or cryptocrystalline chalcedony which is largely
quartz in a very minutely crystalline condition) are often even tougher
than the clear crystallized quartz. Carnelian, agate, quartz cat's-eye,
jasper (containing earthy impurities), and those materials in which
quartz has more or less completely replaced other substances, such as
silicified crocidolite, petrified wood, chrysocolla quartz, etc., are
all nearly as hard and quite as tough as quartz itself, and they make
admirable stones for inexpensive rings of the arts and crafts type.

JADE. Jade, of the jadeite variety, which is rarer than the nephrite
jade, and more highly regarded by the Chinese, is an exceedingly tough
material. One can beat a chunk of the rough material with a hammer
without making much impression upon it. It is also fairly hard, about as
hard as quartz, and with the two properties of toughness and hardness it
possesses excellent wearing qualities in any kind of mounting. True
jade, whether jadeite or nephrite, deserves a larger us