Thomsonite in pebbles occurs with the chlorastrolite at Isle Royal,
but finer stones are found on the beach at Grand Marais, Cook County,
Minnesota. Like the chlorastrolites, they result from the weathering
of the amygdaloid rock, in which they occur as small nodules, and in
the same manner are sold by jewelers in the cities bordering on Lake
Superior to the extent of $200 to $1,000 worth annually.


THE DIAMOND CUTTING INDUSTRY.

In New York there are sixteen firms engaged in cutting and recutting
diamonds, and in Massachusetts there are three. Cutting has also been
carried on at times in Pennsylvania and Illinois, but has been
discontinued. The firms that were fully employed were generally the
larger ones, whose business consisted chiefly in repairing chipped or
imperfectly cut stones or in recutting stones previously cut abroad,
which, owing to the superior workmanship in command here, could be
recut at a profit, or in recutting very valuable diamonds when it was
desired, with the certainty that the work could be done under their
own supervision, thus guarding against any possible loss by exchange
for inferior stones.

The industry employed 236 persons, of whom 69 were under age, who
received $148,114 in wages. Of the 19 establishments, 16 used steam
power. The power is usually rented. Foot power is only used in one
establishment. Three of the firms are engaged in shaping black
diamonds for mechanical purposes, for glass cutters and engravers, or
in the manufacture of watch jewels.

The diamonds used in this industry are all imported, for, as already