Cat's Eye Gemstones

A cat's eye like effect, known as 'chatoyancy', appears to move on this
stone's surface. Cat's eye is a gem variety of chrysoberyl.

There are generally two varieties of cat's eye - the alexandrite cat's-eye
and the chrysoberyl cat's-eye, which is very popular in the Far East,
particularly in Japan. The ideal colors of the chrysoberyl cat's-eye are
yellowish-brown, which is called the honey colour, and the yellow-green,
which is called the apple green colour. A very good cat's eye, apart from
being of ideal color, should have a high degree of transparency and a
well-defined unbroken ray. It should be free from any distracting inclusions
visible to the unaided eye. The chrysoberyl cat's-eye is one of the most
beautiful gemstones because of the "chatoyancy" or the eye effect.

Varieties - Chrysoberyl and Alexandrite, Color change green to red,
Chatoyant, Various shades of green, yellow, brownish, and reddish.

History - Cat's eye has been regarded as a preserver of good fortune. The
natives of Sri Lanka still consider it a charm against evil spirits. British
royalty often use it as an engagement stone.

A translucent variety of chrysoberyl (beryllium aluminum oxide) which
exhibits a silvery white line across the stone. This moves as the stone, the
light source or the observer moves and may appear to open and close like an
eye. The finest quality has a sharp eye that appears to open and close as
the stone is rotated, and exhibits a strong "milk and honey" effect (stone
on one side of the eye appears lighter than the other). These colours switch
as the stone or light source is moved. The most highly prized body colours
are greenish-yellow and brownish-yellow (honey color).
When a gem specimen exhibits both chatoyancy and change of colour, one or
both phenomena will suffer. It is more common to find a good eye with poor
change of color. The conditions necessary for one phenomenon conflict with
those needed for the other. The term cat's eye when used alone refers to
chrysoberyl. Other minerals exhibiting chatoyancy must be qualified, e.g.
tourmaline cat's eye.

Often, the name chrysoberyl is spoken in the same breath as that of the
beryl group, the most well known representatives of which include the
emerald and the aquamarine. The name 'chrysoberyl' comes from the Greek and
means 'gold-colored beryl'. In spite of its name however, it is not actually
a beryl at all. Together with alexandrite, chrysoberyl forms an independent
gemstone, in which the former, which appears to change its colour, is
regarded as the most attractive representative, though in fact it is quite
definitely the chrysoberyl cat's eye which is entitled to stake that claim.

From a mineralogical point of view, chrysoberyls are aluminium oxide
containing beryllium, and thus actually have little in common with the
beryls, which belong to the silicate family. Indeed, with their excellent
hardness of 8_ on the Mohs Scale, they are clearly superior to the beryls.
The popular chrysoberyls come in many nuances between lemon and greenish
yellow, and in honey colors and shades from mint green to brownish green,
and are mostly found in the gemstone deposits of Brazil, Sri Lanka or East
Africa.

Since ancient times, chrysoberyl has been regarded as a gemstone which
protects its wearer and keeps disaster at bay. The cat's eye most of all is
seen as a particularly effective protective stone and talisman. On account
of its golden tones, chrysoberyl is often also associated with wealth - and
this idea is certainly not without foundation, since in its most beautiful
form as a high-quality cat's eye it is up among the gemstones of the luxury
class.

Discipline and self-control are the qualities mainly associated with
chrysoberyl in modern gemstone therapy. Chrysoberyls are said to promote
concentration and the ability to learn, and to enable the wearer to think
clearly and far-sightedly. Thanks to the secret power of the chrysoberyl,
negative thoughts are said to be transformed into positive energy. And these
positive qualities are said to be even more marked with a chrysoberyl cat's
eye. However, chrysoberyl is also regarded as a gemstone which promotes
tolerance and harmony, and it is one of the lucky stones for those born
under the sign of Leo.

Chrysoberyl cat's eyes are genuine rarities which are found only in a few
deposits in the world, together with other varieties of chrysoberyl. One can
hardly imagine that a gemstone could wink like the eye of a cat in such a
remarkably genuine way. Is it magic, or Nature? And apart from that, what is
it that causes this irresistibly beautiful show of light?

Scientists have discovered that very fine inclusions, deposited in the
stone, are responsible for this fascinating phenomenon. The incident light
is reflected off them, so that a bright strip of light appears, running
perpendicular to the inclusions, similar to the eye of a feline predator.
When the stone is turned, this strip seems to glide away across the surface
of the stone. In technical terminology this phenomenon is known as
'chatoyancy', which comes from the French chat (for cat) and oeil (for eye).
Whilst chrysoberyls lacking the cat's eye effect are mostly faceted, cat's
eyes are always cut into cabochons, since only tall, rounded shapes render
the line of the eye properly visible.

The chrysoberyl, with its hues ranging from honey-coloured to mint green, is
a popular gemstone, and one which is esteemed by connoisseurs and gemstone
lovers the world over. In its most attractive variety, the cat's-eye, it is
an extremely valuable stone for those in the know. In general, the value of
a chrysoberyl - as with other gemstones - depends on its quality, that is to
say its beauty, color and attractiveness, the depth of the color and its
transparency. Anyone who wants to acquire a cat's-eye of good colour and
with a finely marked eye-line will be obliged to dig fairly deep into his
pocket, for these gems fetch much higher prices on account of their beauty
and rarity. When buying a cat's-eye, you should be aware of this: it is
important that the 'eye' has a fine line running right through it, and that
it can be recognised clearly. In particularly good specimens, it seems to
open and close when the stone is turned. Fine cat's eyes should be of a
distinctive color and be as transparent as possible. The most popular ones
are those of a beautiful honey yellow and those with fine green tones.

Chrysoberyl cat's eyes are among the most beautiful things that Nature has
created. Again and again, they fire the enthusiasm of those who are looking
for something individual and unique. Cat's eyes are also well suited to
being worn as jewellery by men. And without doubt, there is many a man who
has allowed himself to be seduced by a beautiful cat's eye too

Until recently the main producers of fine quality chrysoberyl were Brazil
and Sri Lanka, but now much more productive mines are in Madagascar and
Tanzania. Because Sri Lanka Chrysoberyl has the finest quality and high
value most of the Madagascar rough is sold as genuine Sri Lanka stones.

When choosing a Chrysoberyl gemstone, due to the pastel color of
chrysoberyl, special attention should be given to the cut and overall
proportions of the stone. When choosing a cat's eye gemstone priority should
be given to the ray or eye of the stone.