r on the "floors" until
it crumbles, then crushing and washing it and concentrating the heavy
minerals by gravity methods. Large diamonds are then picked out of the
concentrates by hand and small ones and fragments are removed by the
"greasers," which are shaking tables heavily smeared with grease over
which the concentrates are washed and to which diamond alone, of all the
minerals in the concentrate, sticks. The grease is periodically removed
and melted, and the diamonds secured. The grease can then be used again.

German South West Africa furnishes a considerable output of very small
diamonds, which are found in dry sand far from any present rivers. These
diamonds cut to splendid white melee and the output is large enough to
make some difference in the relative price of small stones as compared
to large ones. The South West African field seldom yields a stone that
will afford a finished quarter-carat diamond.

RUBIES. Passing on to the occurrence of the _corundum_ gems we will
consider first the _ruby_. Most fine rubies come from Burmah. The
district in which they are found is near Mogok. Practically all the fine
pigeon-blood rubies come from this district. The fashion for red stones
being for the time little in evidence rubies are not now in great
demand. This cessation of demand can hardly be laid to the competition
of the scientific ruby, for the sapphire is now very much in vogue, yet
scientific sapphires resemble the natural ones even more closely than do
the rubies.

Siam furnishes a considerable number of dark garnet-like rubies. These
do not command high prices. They are, however, sometimes very beautiful,
especially when well cut for brilliancy, and when in a strong light.

Ceylon furnishes a few rubies and a few red corundums have been found in
North Carolina.

The Burmese rubies appear to have been formed in a limestone matrix, but
most of those obtained are gotten from the stream beds, where they have
been carried by water after weathering out from the mother rock.

The rubies of Ceylon, too, probably originated in a limestone matrix,
but are sought in stream gravels.

SAPPHIRES. Fine blue sapphires originate in Siam in larger numbers than
in any other locality. Kashmir, in India, also supplies splendid
specimens of large size. Ceylon, too, furnishes a good deal of sapphire,
but mostly of a lighter color than the Kashmir sapphire. The Ceylon
sapphires are found in the streams, but originate in rock