INHERENT QUALITIES 119
flective
power of the stone on the face of it, as a further improvement, he
ground off the apex of the octahedron to a flat facet, making what we
now call the " table," and took the tip off the corresponding point.
This gave a square jewel with a large and a small flat facet parallel
to each other, and from each of which four sloping facets spread to
meet at the edges of the square, ten in all. To yet further increase
the surface reflections of the stones, the corners of these sloping
facets were ground off, thereby forming on top, four equal pentagonal
facets extending from the central flat facet to the corners of the
square, and four shaped like a keystone between them, extending to the
sides. This arrangement changed the shape of the flat facet from a
square to an octagon. The under side facets were cut to correspond, so
that with the two flat facets there were eighteen in all. The large
flat one on top was called the " table," the smaller one underneath,
the " culet," and the others the " side facets." The space between the
table and the girdle came to be known as " bizel," and that between the
girdle and the culet, the " pavilion " or " collet side."
From
these primitive forms there was a gradual addition, in the effort to
increase dispersion of the light rays, to the number of facets, and a
tendency toward the rounding of the finished stone. Material
improvement was slow, however. Large stones were scarce in those days,
and the aim of the cutter was to produce as large a finished diamond
from the crystal as possible. The added brilliancy arising from an
increase in the number of facets, gradually forced the necessary
sacrifice of material, and they were increased to thirty-four,
variously arranged. Some of the old square cut brilliants
