r was then asked if there must not be some difference in the
real nature of the two lots to justify paying more per carat for small,
imperfect stones than per pennyweight for large perfect ones. He of
course acknowledged that it would appear reasonable that such was the
case. He was next shown that his small _true topazes_ scratched his
large stones easily, but the large ones could get no hold upon the
surfaces of the small ones. (It will be remembered that topaz has a
hardness of 8, while quartz has a hardness of 7.) The explanation then
followed that the two lots were from two entirely distinct minerals,
topaz and quartz, and that the former was harder, took a somewhat better
polish, and was more rare (in fine colors) than quartz. Of course the
yellow quartz should be sold under the proper name, _citrine quartz_.
(From the same root that we have in "_citrus_" as applied to fruits.
For example the "California Citrus Fruit Growers' Association," which
sells oranges, lemons, grape fruit, etc. The color implication is
obvious.) If the jeweler still wishes to use the term "topaz" because of
the familiarity of the public with that name, then he should at least
qualify it in some way. One name that is current for that purpose is
"Spanish topaz," another is "Quartz-topaz." Perhaps the latter is the
least objectionable of the names that include the word topaz.

Some of the wine yellow true topazes lose the yellow, but retain the
pink component, on being gently heated. The resulting pink stone is
rather pretty and usually commands a higher price than the yellow
topazes. Such artificially altered topazes should be sold only for what
they are, and probably the name "pinked topaz," implying, as it does,
that something has been done to the stone, is as good a name as any.
There is, however, little chance of fraud in this connection, as
natural pink topazes are not seen in the trade, being very rare.

Some bluish-green topaz is said to be sold as aquamarine, and this
confusion of species and of names should, of course, be stopped by an
actual determination of the material as to its properties. Lacking a
refractometer, the widely differing specific gravities of the two
minerals would easily serve to distinguish them.

LESSON XX

THE NAMING OF PRECIOUS STONES (_Concluded_)

BERYL, EMERALD, AQUAMARINE. Coming now to _beryl_ we have first
_emerald_, then _aquamarine_, then beryls of other colors to consider.
There is too of