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 THE
BIRTHSTONE for JULY
The 15th and 40th
ANNIVERSARY STONE
The 80th ANNIVERSARY JUBILEE STONE
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MOH's scale of hardness
: 9 |
Specific Gravity : 3.97-4.05 |
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Refractive Index : 1.766-1.774 |
Double Refraction : -0.008 |
Ruby is one of the symbols of love.
Ruby is of the mineral Corundum as is Sapphire. The red color
is called Ruby. Some gem dealers debate the borderline between ruby and
pink sapphire. Historically, the word ruby referred to shades of red,
which technically included pink. But the names ruby and pink
sapphire reflect a bit of a difference in value. That’s why, given a
choice, a gem dealer would prefer to be able to call a corundum gem ruby rather
than pink sapphire. Pink Sapphire is really just Light Red Ruby. The
International Colored Gemstone Association passed a resolution that the
light shades of the red hue be included in the category Ruby since it was
too difficult to legislate where red ended and pink began. In practice,
however, pink shades are now known either as Pink Ruby or Pink Sapphire. Either
way, these gems are among the most beautiful of the corundum family.
Ruby hues range from
strongly purplish-red to orangy-red. The finest ruby has a slightly
purplish-red to pure vibrant red hue. As the hue becomes more purplish or
orangy, the ruby moves down the quality scale into good and commercial ranges.
The highest-quality rubies have vivid saturation.
Medium
tone to medium-dark tones are preferred as long as the tone is not so dark that
it has a negative effect on brilliance. At the other extreme, if the tone
is too light, the stone is considered pink sapphire, even if saturation levels
are high. The most valuable ruby colors are red
(R) to
slightly purplish red
(slpR)
with medium (5) to medium-dark (6) tones and strong (5) to vivid (6) saturation.
Typically these are called Cherry Red to Pigeon Blood Red colors. Chrome imparts the Redness to Ruby.
Here are charts showing the GIA master hue/tone/saturation to determine if corundum is ruby, or if it’s pink, purple, or orange sapphire.
Gem Laboratories that use the GIA scale, grade on the principle that red must be the
dominant hue before a stone can be called a ruby, and since
identification of the dominant hue is subject to personal perception, in some
areas of the world pink sapphires are considered rubies. Ruby is an excellent choice
for jewelry and has a high refraction which produces a bright stone.
Ruby's relative density is high, so a one Carat Ruby will be smaller in
millimeter dimensions than a one Carat Diamond.
We typically offer only the finest Burma and Ceylon Rubies. The
Mogok region in Burma, or Myanmar, is the source historically for the
finest Rubies. Ceylon (Sri Lanka), and Mong Hsu Burma Rubies
are what we would consider the regions producing the next to the finest grade
Ruby, whereas Rubies from Thailand, Africa and Vietman are typically in the
commercial grade of Ruby. Facet grade Ruby stones are usually cut in the Cushion or Oval shapes.
Native cutters take liberties with the cutting of the pavilions or back
side of Rubies to produce larger stones by lifting out dark inclusions,
sometimes
leaving small cavities (or divets), allowing the culet or bottom point to be a
little bit off-center, or by having deeper or shallower than ideal pavilions.
Generally these minor points are not noticeable when the stones are mounted, and
generally they do not affect the price. Precision cuts required for designer
jewelry are cut by strict standards, and consequently the cutting adds to the
overall cost of the item.
Ruby was the first mineral to be produced by commercial Gem synthesis
and dates to the 1880's. Many customers have brought family heirlooms for insurance only to be told
that their "Gem" is not a natural stone, so just because it's old doesn't
mean it's the real thing. We have only genuine natural Ruby, so you
will not find synthetic Ruby, among our Gemstones.
COLOR - The most important factor in the
value of a RUBY. The top qualities are as red as you can imagine:
a saturated pure spectral hue without any overtones of brown or blue.
After color, the other factors which influence the value of a ruby are
clarity, cut, and size. There are many variables in colored gem pricing
because it's not a controlled market like the diamond market is.
One dealer may sell an Ruby of the same quality at one price and another
dealer may sell that same Ruby for another price. There is no price
guide as in diamond purchasing. Whatever a dealer can get for that
rarer colored gem is what it's worth and if he wants to hold out for a
certain amount of money he just has to hope he's making the right
move. So you need to be educated enough to know what you're doing!
Since we cut out these middleman dealers, you can expect to get a great
quality stone for considerably less.
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