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What is a ruby?


#1

All, These discussions leave quite a discrepancy for me that goes
right to the basics of color in Every reference that I
have read about corundum states that the only way that red color is
perceived in corundum is by the addition of chrome to the corundum.
No other mineral will cause the red color. GIA and European gem labs
also support this. But, GIA also makes a statement that all red
corundum is ruby. Which means that all ruby must contain chrome. By
this logic iron cannot color corundum red, only chrome. I assume
that both GIA and European labs have conducted extensive tests on red
corundum from many locations to arrive at this decision, including
Umba. Therefore, to me the red corundum from the Umba deposits 1.
must contain chrome 2. Must be ruby, or 3. GIA and European gem
laboratories are incorrect in their nomenclature of what is a ruby.
Quite simply both labs state that the only corundum that can be
classified as ruby is red and must be colored by chrome. So, What is
a Ruby?

Gerry Galarneau


#2

Rubies are red corundum. But not all corundum are rubies. If a
stone fails the “red” test by the failure to have chrome it is a
sapphire. Originally, stones were classified by color. However, this
created confusion. Two stones that were easily confused were red
corundum and red spinal. Thus, not all red stones are “rubies”. The
word ruby is derived from the latin word for red and not all corundum
is a ruby? Mike


#3

Michael,

    Rubies are red corundum.  But not all corundum are rubies.  If
a stone fails the "red" test by the failure to have chrome it is a
sapphire.  Originally, stones were classified by color.  However,
this created confusion.  Two stones that were easily confused were
red corundum and red spinal. Thus, not all red stones are  "rubies". 

I think your logic is slightly flawed here. Rubies are red corundum.
Not all corundum are rubies. But all red corundum IS ruby. Ruby and
spinel are not related at all and, while historically they were often
confused, they aren’t very often anymore.

Daniel R. Spirer, G.G.
Spirer Somes Jewelers
1794 Massachusetts Ave
Cambridge, MA 02140
617-491-6000
@spirersomes
www.spirersomes.com


#4

All red corundum is NOT ruby. If it contains chrome and the
absorption lines show in a spectrometer then it can be classified as
ruby. If it does not it is red corundum or red sapphire (you choose)
and in the EEC it’s illegal to sell it as ruby.

Tony Konrath F.G.A. (see, I put my qualifications in!)
Gold and Stone
www.goldandstone.com
tony@goldandstone.com


#5

Greetings Orchidians,

For the last forty five years, I’ve been an amateur mineralogist,
lapidary, and jeweler. I’ve been a member and lurker on this list
almost two years. It’s been wonderful to see all the technological
advances, especially the synthesis of gems and the understanding of
the physics and chemistry of gems.

There has been a disturbing trend developing in the industry, that I
first noticed with the green beryls. I was ok with the distinction
between green beryl and emerald, iffy as it may be. However, the ruby

  • red sapphire pseudo-distinction has prompted me to write my first
    e-mail to this group. I call this trend “counting angels on the head
    of a pin.”

The names and identities of many familiar gems come from antiquity,
long before we had technological means for identification. Ruby was
accepted as a hard clear or asterated stone within a certain range of
the color red. Then we discovered the chemical nature of different
mineral species and we excluded spinel and some garnets from the realm
of ruby - ruby is corundum. Ok. In all the common literature until
recently corundum within a certain range of red is ruby, all other
corundum is sapphire. We’ve known for over a century that chrome as a
dopant will cause corundum to be red/ruby. That’s what is used to make
synthetic ruby. Recently we’ve found out that at least one other
dopant can color corundum red and can probably be found to be the
colorant in many other recognized rubies. Since the long standing
definition of ruby as red corundum as distinct from all other colors
of the same mineral species is already arbitrary but clear enough,
then the motivation for even finer distinctions based on dopants has
an unworthy motivation. I believe that certain aspects of the industry
are using the ability to make finer and finer distinctions as an
exclusionary method to buoy the prices of certain rubies and keep the
supplies small enough to justify the high prices. This prevents some
people from rightfullly benefitting from their discovery and
exploitation of non chrome rubies. What is the industry going to do
when rubies are discovered that contain both chrome and other red
causing dopants. The chrome spectroscopic signature will be there,
therefor they’re rubies. Right? What if the majority of the dopants
are other than chrome? Like the situation with the garnet and feldspar
families, the majority species determines what it is called. With more
non chrome dopants, these stones are sapphires not rubies. This is
pure speculation on my part, but it carries the "counting angels"
logic a little farther, in the hope of helping us to think about the
absolutes we get cornered into defending. It is always my goal to get
people to question their assumptions, even their sacred cows. Better
thinking comes from this. On the question of when is a ruby not a
ruby, remember that almost all of the people on this earth are unaware
of this as a real problem. If they were aware of it, they wouldn’t
care in the slightest about it’s resolution.

I have not meant to offend anyone with my references to “angels” and
"sacred cows." If I have, I apologize. I really do try not to be
ethnocentric or oppressive. In these dangerous times, we really need
to develope our sense of humor. If we get too serious we’ll be at a
disadvantage in combatting racism against all the loving and
contributing arab and Islamic peoples of the world as well as
combatting the oppression of all the loving and contributing jewish
peoples of the world. We can’t allow ourselves to be driven by
revenge now. We have real opportunities to do things differently in
this new millenium. I encourage us all to take the offered
opoportunities. Enough.

Love to you all and peace, Marty Wittstruck