We have continually emphasized that Yogo sapphires are all natural and
not color or clarity enhanced. Do you know why? What does it mean to
say that a sapphire is guaranteed natural? This page explains the
uniqueness and rarity of Yogo sapphires in more detail.
Gemstones are valuable due to their beauty, rarity and demand. In the
face of the dwindling world sapphire reserves, man has developed
artificial "cooking" methods to enhance the appearance of lower quality

According to the Jewelers Vigilance Committee, JVC, a non-profit
organisation, 95% of sapphires on the market today have been heat
treated. Heat treatment enhances lower quality sapphires by deepening
their color to hide the imperfections, however, heat treatment also
causes a reduction of the natural sapphire's brilliance and transparancy.

In order to maintain a high professional standard and credibility, the JVC
and Federal Trade Commission, as well as many dealers, gemologists
and jewelers, believe that heat treatment of sapphires should be
disclosed to the consumer.
Conversely, untreated sapphires should be certified and guaranteed as

The Yogos supplied to you at this site come with such a certification and
guarantee. They have not been processed or "cooked" in any manner,
thus, no
color, brilliance or transparency has been lost. Their beauty is all natural.

Both sapphires and rubies are a variety
of the specie corundum, a mineral, and
are essentially crystallized aluminum
oxide (Al2O3).

As most corundum is colorless
(allochromatic), only the small
proportion of corundum that is colored
is of value and in demand. The color of
the corundum depends on the metals
that are present during the time of

When chrome is present at the time the
corundum crystalizes, red is created
and the resulting corundum is known as
ruby. The depth of red determines
whether the variety is a ruby or pink sapphire.

When titanuim, vanaduim and rutile are present, blue is created. The
result? Blue sapphires.

Corundum containing other trace metals appear in a wide spectrum of
colors, including violet, green, yellow and orange and are all referred to
as sapphires.

Thus, ruby is a variety of corundum while every other color of corundum
is sapphire and is also a variety of corumdum.

Because nature does not always control its temperatures and pressures
to the exactness of a laboratory, blue sapphires sometimes crystallize at
a temperature that does not melt the coloring agents. These sapphires
are pale blue or white. To enhance the clarity and the color of these pale
or white sapphires, they are heated until the rutile melts which triggers
the coloring mechanism.

The prudent consumer should always demand from the seller of any
sapphire to
declare if the sapphires offered for sale are color and/or clarity enhanced
so as to
make their own determination of what they are purchasing.
Above) Photo of a stove used to heat treat
non Yogo  sapphires. I think I would prefer for
mother nature to do the cooking.
Copyright© 1998 sapphire-untreated.com, Spokane, WA 99210 all rights reserved
Home of Yogo Sapphires
All Natural Yogo
Copyright© 1998 sapphire-untreated.com, Spokane, WA 99210 all rights reserved