Understanding Sapphires
Sapphire is one of the hardest natural gemstones. It belongs to the class of minerals called
Corundum - second only to diamond in its hardness. When it is red, it is called sapphire, but sapphire
is also available in other colors, although blue is the most popular. Unlike diamond, which is made
of carbon, sapphire is a combination of aluminum and oxygen.
Sapphires are so rare and expensive that cutters tend to shape them into ovals or cushions instead
of round shapes (more popular in diamonds). Ovals and cushions preserve most of the original rough.
Round sapphires are also popular, but their final shape involves removing a lot of rough and they
therefore tend to be more expensive than ovals and cushions. The following styles of sapphire are
the most popular:
Step Cut/Emerald Cut
Rows of facets are cut parallel to the sapphire's edge resembling the steps of a staircase. When the corners
of the sapphire are clipped, the shape is referred to as an 'emerald' cut. 'Emerald' cuts protect the corners
of the sapphire.
Brilliant Cut
The facets on brilliant cut gems are triangular, kite or lozenge shaped. A brilliant cut sapphire can have a
varying number of facets, but when cut like a diamond, it will have 58 facets. This diamond-cut will not
make the sapphire "sparkle" as much as other cuts, mostly because of the difference in light refraction and
intensity of color between sapphires and diamonds.
Mixed Cut
The mixed cut combines step and brilliant cut facets and
is the most common faceting style for
sapphire. The crown is usually brilliant-cut to enhance sparkle. The pavilion is usually step-cut
to save weight and enhance the stone's color.
Cabochon Cut
Antique jewelry often features cabochon (Kab-a-shon) sapphires, cut in a convex form (domed with a flat base)
and highly polished but not faceted. Cabochon cuts are the simplest, and are therefore the least expensive
of the sapphire cuts.
Other cuts and carvings (designs cut into the sapphire) also exist, but they are less popular and are not dealt
with here.