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Pink Sapphire or Pale Ruby?


#1

Was: Using the term semi precious gems

Dear Andrew,

Of course, then they'd have to think of another marketing
description for pink corundum - anybody want to buy some
"albino-eye" rubies? 

Sorry, it was I who was guilty of the “pigeon blood red” ruby faux
pas and I humbly stand corrected and suitably reprimanded (I speak
sincerely but also a little tongue in cheek, ie. I don’t take such
corrections personally - at least not anymore).

However, this brings up what will probably be yet another of my
stupid questions (yes I know there are no such things). When talking
of pink corundum, where does one draw the line between the paler,
pinkish rubies and pink sapphire? Is it a pink sapphire if it’s clear
and a pink ruby if it’s opaque? I don’t wish to open any worm cans
but it does puzzle me slightly and I’m sure someone out there knows
the simple answer.

Helen
UK


#2
When talking of pink corundum, where does one draw the line between
the paler, pinkish rubies and pink sapphire? 

Pink Sapphire or Pale Ruby? by Ted Themelis
https://orchid.ganoksin.com/t/gemlab-report-pink-sapphire-or-pale-ruby

One of the most controversial and still unresolved issues for the
gemological community is the appropriate definition of, or
relationship between, pink sapphire and ruby. Generally, in the
marketing of color designations of ruby and pink sapphire
tend to refer to rubies as gems that are medium to dark red to orange
or purplish-red and to pink sapphires as pale to light red. Both
gemstones are, of course, color varieties of corundum.

The issues.

The question of definition arises because of three major issues:

  1. Whether or not pink sapphire should be considered as an individual
    color variety of corundum.

  2. If each color variety is to be considered separately, at what
    point the demarcation line between ruby and pink sapphire occurs?

  3. What are the proper lighting conditions to be used to determine
    their exact color?

Gemstone dealers and jewelers have argued on these issues for years.
The goal of many dealers is to buy the gem as pink sapphire and sell
it as ruby, because in most cases rubies are considered more valuable
than pink sapphires and therefore produce more profit.

Historical aspects.

Before any attempt would be made trying to resolve this problem, it
might be wise to look at the historical aspects of the issue. Max
Bauer, in his Precious Stones (1896), gives the following definition
of ruby:

“The tone of color (in ruby) differs in different specimens, being
sometimes deep and intense, sometimes pale and light. The lighter
shades vary from pale rose-red to reddish-white, some specimens being
so faintly tinged with red as to appear almost colorless. The darker
colors are pure red, carmine-red, or blood-red; the red of the
majority of rubies, however, has a more or less distinct tinge of
blue or violet, this being specially noticeable in transmitted light.
The shade of color most admired is the deep, pure carmine-red, or
carmine-red with a slight bluish tinge.”

A few years later (1909), Julius Wodiska describes ruby in his Book
of Precious stones:

"The color-tone of the ruby varies greatly, and the presence of
deep, intense tones of red causes the term 'masculine' to be
applied to a gem while the paler tints suggest the term
'feminine.' Rubies range from a delicate pink tint through pale
rose-red to reddish-white, pure red, carmine red, or blood red. A
tinge of blue or violet is frequently discernable in these
shades." 

So, here we have introduced the designations “masculine ruby” and
"feminine ruby"! Although the term “pink sapphire” has not been
mentioned so far, there is an indirect attempt to separate the deep
red corundum’s (“masculine”) from “feminine” rubies, the lighter red
corundums. Some speculation has it that the “feminine” ruby
represents Sri Lankan material, while “masculine” ruby represents
Burmese or Thai material. Obviously, such designations were devised
to emphasize the existing differences between “masculine” and
"feminine" rubies and to prevent potential misunderstandings.

Early reference to pink sapphire in gemological literature is given
by G.F. Herbert in the sixth edition of Gemstones (1930):

"The tint of the red stones varies considerably in depth;
jewelers term them, when pale, pink sapphires, but of course, no
sharp distinction can be drawn between them and rubies." 

From that time until now, the designation “pink sapphires” has
appeared in every gemological publication. Reference to it is made,
for example, even by R.M. Shipley in The Dictionary of Gems and
Gemology:

"Ruby. The red variety of corundum. Intense, medium to medium
dark purplish red (so-called pigeon's blood) is best, intense red
is fine, and dark red is less desirable. Star ruby is rare. In
the jewelry industry, the finest purplish-red stones, principally
from Burma, are known as 'Burma,' or 'oriental rubies'; less
valuable, darker red, principally from Thailand, as 'Siam
rubies'; and light red, from Ceylon and elsewhere, as 'Ceylon
ruby' or pink sapphire." 

R.Webster describes ruby in his monumental Gems (4th ed.,1983) as
follows:

"Ruby varies in shade from a pale rose tint through all shades of
red to a deep crimson sometimes known in the jewelry trade as
'black.' The pink colored corundum may be considered as a pale
ruby but a pure pink colored stone is known as pink sapphire, all
fancy colored corundum's being termed sapphire with the color as
prefix. The decision whether a stone is pink sapphire or pale
ruby may often lead to debate." 

Discussion.

The need to define ruby specifically as a color variety of the gem
species corundum is obvious, whether the material is called
"masculine ruby", or “oriental ruby”, or “Sian ruby”, or anything
else. Yet one side in the debate over names argues that since pink
sapphire is light red - rather than a different color completely -
there should be no distinction made between ruby and pink sapphire at
all. In fact, the Asian Institute of Gemological Sciences (AIGS) in
Bangkok, Thailand, has abandoned the use of the pink-sapphire
designation (as an individual variety of corundum) from its
educational programs, as well as from the gem-identification reports.

The opposing side argues that pink is an entirely separate color
designation from red, with the “separation line” between pink
sapphire and ruby precisely defined. Those who adopt this position
argue that a distinct classification of pink sapphire as an
individual variety of corundum is sound, since designations for other
separate categories of sapphire, such as “orange” and "purple"
sapphire, do exist and are necessary.

Color grading.

The need for a universally accepted and practically workable color
grading system for gemstones is obvious and will resolve many
problems including the “ruby or pink sapphire” issue. In the past,
several color grading system have been introduced, consisted from a
series of “master” reference points -in the form of a set of color
chips, or chart of color samples, or a tri-dimensional substance that
silulates a gemstone. However, in practice, they never meet the
strict criteria of proper gemstone color grading.

It is the author’s opinion that, the color-grading problem may be
solved using C.I.E. chromaticity coordinates emanating from
spectrophotometer readings. Representing the tristimulus values of
the visible color spectrum, these readings should be the basis of
fabricating a tri-dimensional object that will simulate a
"reference-point gemstone" that may be called master. These masters
shall be fabricated from suitable material taken into consideration
transparency, luster, refractive index, fluorescence and all other
appearance attributes characteristic to ruby and pink sapphires.
Since it is impossible to produce all the colors of ruby and
sapphire, the best method is to fabricate sufficient number of
masters that represent the most frequently occurring colors and
appearance in ruby/sapphire based on their country of origin.

Thus, direct comparison between the color of the gem and the “master"
is possible. Series of these “masters” may consist of a so-called
"color matching system”. Certain number of these “masters” may
represent a range designated as an individual variety (pink sapphire)
of corundum, while other masters may represent the ruby designation.
There should be a “master” that would represent the “transition
point” - that is, the cut-off point that separates pink sapphire from
ruby. Thus, pink sapphire may be defined as having less that 50% of
the color component needed for a gemstone to qualify as ruby.

Lighting conditions.

Equally important, is the need for a standardized and universally
accepted light source. The apparent color of rubies and pink
sapphires is, to some degree, influenced by fluorescence stimulated
by ultra-violet rays of sunlight. Thus, rubies and pink sapphires
appear different in Southeast Asia from how they do in locations in
the Northern Hemisphere, say New York or London. But, in reality, to
persuade Sri Lankan and Thai dealers to use a designated light source
will be a nearly impossible task. A suitable light source for proper
color grading should have the following spectral properties:

Color Temperature above 5,500oK

Color Rendering Index (CRI) above 90

Harmonic spectral distribution in the ultraviolet and visible region
of the e-m spectrum.

There are several lamps readily available in the market that meet
above criteria. Try the 18" long “Vitalite” by DuroTest Company, or
"Daylight-99" by Mitsubishi.

NOTE: Please refer to page 19-20 of my book “The Heat Treatment of
Ruby & Sapphire” for full discussion on lighting sources.

The effect of heat-treatment.

A final comment on this issue should center on the effect of
heat-treatment on pink sapphires and rubies. The author has
successfully performed many experiments on removing the purple and
brownish-overcast color from rubies and pink sapphires. The results
were very interesting, especially when the color fell on or about the
transition point: On some rubies, the removal of purplishness
produces a purer, lighter-red coloration that prevents the substance
from being considered ruby any longer, but it appears as pink
sapphire. The paradox was that although the value of the ruby should
have being increased as a result of the removal of the undesirable
brownish tinge, its actual value may be decreased (or remained the
same), because the stone is considered by many dealers as pink
sapphire.

Since problems like this persist, the author wishes to salute
organizations, as well as various individuals in the gemological
community, who actively raise questions about the whole issue and
seek to provide solutions. So far, unfortunately, apathy on the part
of various trade, jewelry, and educational organizations blocks a
sound solution from being accepted.

Yet, the issue does need to be resolved. With prices of gemstones
escalating rapidly, the game of “buying pink sapphire and selling it
as ruby” needs immediate attention. (The same game could easily occur
with other gemstones as well: “buy it as green beryl; sell it as
emerald.”) If a cure is ever finally offered by the jewelry industry,
I simply hope that the solution chosen won’t ultimately be worse than
the “disease” itself!


#3

red with no pink or purple overtone is ruby, pink is sapphire.

Richard Hart


#4
Is it a pink sapphire if it's clear and a pink ruby if it's opaque? 

Excellent question!

Pink as a colour does not exist. Pink is a de-saturated red. When gem
is evaluated for colour, GIA used 6 categories of colour intensity (
how much colour is present ). In order to be called a ruby, the
colour must be 3 and above. Everything below 3 is a pink sapphire.
Whether gem is transparent, translucent, or opaque, has not bearing
on the colour grade.

Leonid Surpin


#5

Hanuman,

Thank you for the well thought out arguments concerning Ruby and
pink Sapphire.

Since corundum is one of my favorite I have had many
discussions with clients over the years concerning the fine line
between pink sapphire and ruby and the huge financial implications
that may result. I must add that although I too believe a standard
needs to be set using lighting that will produce the same results
anywhere in the world, there is still the problem of color perception
between one individual and another.

No matter how a gemstone is described, in this case Sapphire as
compared to Ruby, the simple fact is that color, clarity, rarity,
cut and durability are the factors that make a gemstone beautiful and
not it’s title. I will take a medium pinkish red Sapphire that has
been well cut with lots of brilliance any day over a cloudy red and
lifeless ruby.

Thank You Hanuman

Greg DeMark
www.demarkjewelry.com


#6

It is very simple in my mind: rubies are red; sapphires can be pink.
However, I also view blue sapphires with the same simplicity: they
should not be black/blue; not opaque; not “denim blue” but a
eye-catching vibrant blue that takes one’s breath away; a version of
blue fire in a shades running from royal blue to cornflower blue;
but in all shades: vibrant.

Cameron


#7

specific gravity test will give you an archaic parameter…but in
general Thai producers/labs have eliminated the “pink sapphire” as a
corundum class on its own…opting for shades and types of ruby
classifications…While stones are sold as pink sapphires,many are
heat treated sapphires that appear pink…there are very few stones
actually categorized/classed as pink by major labs(GIA,AIGS,etc.)
and pink as far as some labs go is a dilute red, so the only way to
know if a dealer is offering you “pink sapphire” would be a specific
gravity test, as colour alone is controversial as far as
classification goes…however, there are reputable sellers offering
pink corundum,clear,and in various shades of red and blue
combinations (on the spectroscopic level) that were sold (and
purchased) before 1980 that are termed pink sapphires. In
thailand,and Africa there have been occasions when I have been
offered pink sapphires,raw and uncut in the field…the miners refer
to them as pink sapphires,they are corundums,and they appear pink-
the same thai miners and/or dealers (dealers in Africa) had rough
mogok ruby(most of the material fairly opaque to translucent),and
various low quality to fairly clear (SI1) light magenta to fuschia
to crimson carmesci rubies that the miners and dealers differentiated
between on their own- in some cases, with no formal training,just
hard work at producing stones for sale from gravel beds in their
farming holds…If they say pink sapphire,and it’s pink and a
corundum,I’m not arguing with the miners,or dealers- just having
them cut,and setting them, and selling them as whatever they told me
they were in the first place…pink is pink- not diluted reds in my
observation of colour! and sapphires are not rubies as I have
learned…If one were to put a geologist,crystallographer,jeweler,and
lab owner in the same room with the same stones and were asked to
write a brief description of the stones shown, I have no doubt they
would all write something different- who’s to say one is more right
than the other as they have all been trained in similar sciences that
are worlds apart…

RER


#8
GIA used 6 categories of colour intensity (how much colour is
present). In order to be called a ruby, the colour must be 3 and
above. Everything below 3 is a pink sapphire. Whether gem is
transparent, translucent, or opaque, has not bearing on the colour
grade. 

Excellent answer! That helps. I’ve seen a lot of “pink” stones that
people are selling as pink rubies and they should obviously be
called sapphires in that case as they are usually very pale or
desaturated in colour.

Thanks again Leonid, it’s all becoming a bit clearer.

Helen
UK


#9

Hi Cameron,

blue sapphires should not be black/blue; not opaque; not "denim
blue" but a eye-catching vibrant blue that takes one's breath away;
a version of blue fire in a shades running from royal blue to
cornflower blue; but in all shades: vibrant. 

This too is helpful thanks. There’s so much junk out there,
especially in the high street jewellers’ windows! So many sapphires
are black/blue and opaque and perhaps most people would associate
such dark “colours” with sapphires and think the beautiful
cornflower to royal blues too pale! I know my (lovely) mother-in-law
would.

Helen
UK


#10

when I took the gem class a long time ago I was told it is what it
is as far as What dose the customer want a pink sapphire or a light
ruby.

Don in Idaho


#11
I also view blue sapphires with the same simplicity: they should
not be black/blue; not opaque; not "denim blue" but a eye-catching
vibrant blue that takes one's breath away 

Well from a gemological standpoint it isn’t the case. From a
realistic standpoint, while all of my sapphires would probably fall
into those criteria, the vast majority of stones out there don’t. Of
all of the customer’s stones (that I didn’t sell them) I have worked
with over the years (and it’s been a lot) I would say that less than
1% would actually be what you are describing.

Daniel R. Spirer, G.G.
Daniel R. Spirer Jewelers, LLC
1780 Massachusetts Ave.
Cambridge, MA 02140
www.spirerjewelers.com


#12
If one were to put a geologist,crystallographer,jeweler,and lab
owner in the same room with the same stones and were asked to write
a brief description of the stones shown, I have no doubt they would
all write something different- who's to say one is more right than
the other as they have all been trained in similar sciences that
are worlds apart... 

That may be, but on this list of jewelers, the only opinion that
truly matters (because we’re jewelers, not geologists) is those of
the gemologists. Last I read, ruby and sapphire were still both
corundum. Ruby is simply the red variety. You can dress it up all
you want, but they’re still both corundum. Just like garnets are
garnets, regardless of color and variety.

Daniel R. Spirer, G.G.
Daniel R. Spirer Jewelers, LLC
1780 Massachusetts Ave.
Cambridge, MA 02140
www.spirerjewelers.com


#13

There is an old jewelers saying. It’s Ruby if you are selling it and
it’s Pink Sapphire if your buying it.


#14
O'Rouurk says " specific gravity--- Can be a distinguishing factor 

all my sources seem to indicate that corundum, sapphire, and ruby all
share the same SG 3.99I only have very old books. What is the
difference

Thanks


#15
all my sources seem to indicate that corundum, sapphire, and ruby
all share the same SG 3.99I only have very old books. What is the
difference 

Actually it is slightly higher, but your point is right on. Even if
there is some difference between ruby and sapphire, it is useless for
practical application. Determination of SG requires very
sophisticated equipment and procedures. Otherwise results are not
trustworthy. The precision obtained on run of the mill equipment is
not good enough.

Stones would give different results depends on the inclusions they
contained as well. At best SG may be used as an indication but in no
way is conclusive.

Leonid Surpin.