not be known what a certain lot of rough mineral will yield when
selected and cut. Some of the figures of production furnished this
office are evidently the values for elaborated gems, while others may
represent but little more than the cost of mining. Aside from the
difficulty experienced in obtaining figures from certain producers,
there is a considerable production of various gems from scattered
localities concerning which little information can be obtained.
table shows an increased production of several minerals during 1907
over 1906. The most important increase is in the production of
sapphire, which was mined m unusually large quantities in Montana. A
substantial increase is recorded in the production of tourmaline and
chrysoprase, and in several minerals produced in small quantities, as
amazon stone, rose quartz, topaz, and utahlite and amatrice. A
substantial production of californite was reported for 1907; no output
was recorded for 1906. Several other gems are listed with a production
in 1907 for which no record was obtained during 1906, as gold quartz,
jasper, pyrite, smithsonite, etc. One new gem mineral from California,
benitoite, was added to the list. Values of the production of such
minerals as diamond in Arkansas, emerald and ruby in North Carolina,
were estimated from outputs reported or seen.
Production of precious stones in the United States in 1906 and 1907.