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Lab creating emeralds


#1

Curious as to when the process of lab creating emeralds began. I
have an old emerald that I am being told was lab created and I
wonder if this is possible due to the age of the stone??


#2

Hello,

Carrol Chatham came up with the process in the mid 1950’s
(comercially). other stones, rubies, were synthesized in the
late/middle 1800’s.

Later


#3

You didn’t say how old the stone was, but synthetic emeralds
have been commercially available since 1956, although Chatham
claimed to have sythesized emerald around 1940. Jerry in Kodiak


#4

Curious as to when the process of lab creating emeralds began. I
have an old emerald that I am being told was lab created and I
wonder if this is possible due to the age of the stone??

  I am going to give up my age here. I remember a segment of
  "You Asked for It" that ran in the early 60's, maybe 1962
  that described the synthesis of emeralds. I can't be
  positive, but I think that Carroll Chatham was interviewed
  for it. Anyone else see this? 

Bruce D. Holmgrain
Maryland’s first JA Certified Master Bench Jeweler
@Bruce_Holmgrain


1-703-627-8580


#5
       Curious as to when the process of lab creating emeralds
      began. I have an old emerald that I am being told was lab
      created and I wonder if this is possible due to the age
      of the stone?? 
  It depends on the type of synthesis used, and it should be
  noted that the history is a bit confused. 

  According to Nassau's "Gems Made by Man", 

  Reports of attempts or patents on processes other than
  flux growth go back as early as 1894, but these processes
  were generally only capable of producing, with difficulty,
  very small crystals, and commercial production was not
  seen until the hydrothermal processes were perfected
  (sorta) by Lechleitner, which appeared on the market about
  1960.  These, though, are a "skin" of emerald grown over a
  base stone of a near colorless natural beryl.  The first
  completely synthetic hydrothermal emeralds to reach the
  market in any quantity were the Linde stones, starting in
  1965.  

  Flux growth techniques, which now account for most the
  synthetic emerald on the market (Gilson, Chatham, and
  others) are based on research that goes back as far as
  1848, with the definitive reports of P. Hautefeuille and
  H. Perrey, 1888 and 1900 paving the way for most future
  work.  At this point, though, crystals grown were only
  about 1 mm in size, and not marketed.  IG-Farben managed
  some commercial production aroud 1934, but only a few were
  released before world war 2 intervened.  Another
  researcher, Richard Nacken, is thought to have produced
  synthetic emeralds around 1928, but Nassau doesn't state
  whether any commercial production was achieved. 

  For most practical purposes however, the first truly
  commercially produced, and commercially successful emerald
  synthesis was that of Carroll C. Chatham.  To quote from
  Nassau: 

  "... Born in 1914, he obtained his bachelor of science
  from the California Institute of Technology in 1938.  For
  the next eight years he worked on the chemistry of food
  processing technology for the firm which is now the Del
  Monte Company. Beginning his provate experimentation while
  still in high school and deciding to tackle the synthesis
  of diamond, Chatham then switched to emerald.  he did this
  because his parents and neighbors objected to the repeated
  explosions from his attempts to grow diamond by dropping
  solutions of carbon in red hot iron into liquid air for
  rapid quenching.  his emerald experiments resulted in his
  first crystal after six years experimentation at age 21,
  while still in college. it took him another three years to
  determine how he had achieved this reulst and how to
  control the process.  At age 25, he had some difficulty in
  convincing jewelers that he had grown these synthetic
  emerald crystals himself. Free to leave his regular job
  with the end of World War II, he devoted himself to
  full-time emerald production.  Furnaces and temperature
  control systems were not at that time the commonly
  available items that they are today and he had to build his
  own, and has continued to do so over the years... ... His
  sons John and Tom are now partners in his enterprises. At
  first his product was slow to catch on.  He was helped
  indirectly bo the Jewelers Vigilance Committee which
  objected to the designation "cultured emerald" which he
  used for marketing purposes.  The FTC disallowed this
  usage, but gave him permission to use the term "Chatham
  Created Emerald in 1963... " 

  So then.  The answer to your question is that they were
  readily avialable as Chatham flux grown gems after the war,
  and after 1960, as hydrothermally grown stones.  Some
  limited stones were produced before the war, but not
  commercially released outside of the small amount sold in
  Germany in the 30s.  

Hope this helps.

Peter Rowe


#6

To add to Peter Rowe’s writeup on synthetic emeralds there is a
very interesting four page article on “Hot Rocks” published in
the NewScientist of 28 Febuary, 1998, a popular and informative
UK weekly magazine on science. This magazine should be
available in you local library.

The introduction says “There’s a secret to cooking up the
perfect fake diamond or emerald. Whatever your brand of
alchemy, throw in a few flaws, says Amy Adams, or the gem police
will get you.”

The first synthetic gems - rubies and sapphires were made by
French chemist Aguste Victor Louis Verneuil at the turn of the
century.

Carrol Chatham started his pioneering work on emeralds in 1926
and his son Tom has carried on his father’s business
distributing lab grown rubies, sapphires and emeralds from his
San Francisco office.

I have skipped retyping the detailed technical descriptions on
chemistry and tests to identify synthetic gems but one
interesting statement is “After a long wait-it can take over a
year to grow marketable stones-out came emeralds.”

General Electric and De Beers have been growing diamonds for
industrial use since 1955, but these tend to be yellowish-brown
or blue in color. Officially sold only for industrial use,
gemnologists have seen a few synthetic diamonds masquerading as
real gems… Russians have made synthetic white
diamonds which are marketed through Chatham …flouresce a
yellowish- green color under ultra violet light while natural
diamonds emit either blue or a weak yellow light. The synthetic
also contain iron impurities from the growth chamber. The clue
is a dark reflective inclusion, which hints at the inclusion of
iron. And there’s a simple test to confirm it, says Shigley*.
You just dangle the diamond on a string and hold a magnet next
to it. If it moves, you’ve been had.

*James Shigley, director of research at the Gemological Institute of
America.

Kelvin Mok (klmok@shaw.wave.ca)

Home: (780) 463-4099 | Home FAX: (780) 430-7120


#7

Hello,

Synthetic Emerald crystals were successfully developed by French
and German chemists Hautefueille and Perry in 1888, by a flux
technique.

I.G. Farbenindustrie followed up on their work and by 1935 were
producing synthetic emerald using a flux-reaction technique.
Production was stopped in 1939 due to World War 2.

In 1938, American chemist Carroll Chatham, successfully created
synthetic emerald and was first to produce it commercially by
the flux-melt growth method.

In 1960, Leichleitner produces hydrothermal synthetic emeralds.

In 1963, Pierre Gilson, in France, produces high quality
synthetic emeralds, improving the flux grown method by a flux
transport technique.

In the 1960, Linde Air Products produces hydrothermal synthetic
emeralds, in 1970, the Cie is sold to Regency.

And more recently fine quality synthetic emeralds have been
produced by both flux and hydrothermal techniques :

  • Kyocera, 1970, Japan
  • U.S.S.R, 1979
  • Lennix, 1980, France
  • Biron/Pool, 1985, Australia

Best Regards,

Francoise.


#8

I remember the segment on You Asked For It (that was my favorite
program) but I wasn’t sure what the stone was - but YES it was
Carroll Chatham being interviewed. There I’ve told my age too!!

Lorri Ferguson
fredlori@worldnet.att.net


#9

When we lived in the San Francisco area, I heard that Chatham
used to dump his batches of imperfect stones out in the bay.
Won’t that be interesting for a geologist to discover in the future!


#10

Hello, Synthetic Emerald crystals were successfully developed by
French and German chemists Hautefueille and Perry in 1888, by a
flux technique. I.G. Farbenindustrie followed up on their work
and by 1935 were producing synthetic emerald using a
flux-reaction technique. Production was stopped in 1939 due to
World War 2. In 1938, American chemist Carroll Chatham,
successfully created synthetic emerald and was first to produce
it commercially by the flux-melt growth method. In 1960,
Leichleitner produces hydrothermal synthetic emeralds. In 1963,
Pierre Gilson, in France, produces high quality synthetic
emeralds, improving the flux grown method by a flux transport
technique. In the 1960, Linde Air Products produces hydrothermal
synthetic emeralds, in 1970, the Cie is sold to Regency. And more
recently fine quality synthetic emeralds have been produced by
both flux and hydrothermal techniques : - Kyocera, 1970, Japan -
U.S.S.R, 1979 - Lennix, 1980, France - Biron/Pool, 1985, Australia
Best Regards, Francoise.


#11

Add to Kelvin Mok’s supplement on emerald. It is true that
Chatham emerald takes about one year to grow but synthetic Biron
emerald takes shorter time (2 weeks) to grow a 44 carats size
emerald crystal. Biron used the hydrothermal method.

About the synthetic diamond, the simple identification is just
only a consolation for most people. Last week, I was given the
chance to look at 8 pieces of synthetic diamond by De Beers (on
loan) and found that some of their yellowish-brown diamonds do
not fluoresce under UV light (short or long wave). Your magnetic
method for separating natural from synthetic diamond may not be a
fool proof method too. Why? Only the large metallic inclusions
will be attracted to the magnet and I found two pieces with
large metallic inclusions were able to do that. The rest, which
is quite clean i.e. dust-like inclusions, just do not stick to
the magnet. What next you may ask? Use diamondsure or
diamondview invented by De Beers, hopefully for use in the
future. Both instruments are not for sale. Other methods of
test are FTIR or EDX.

With best regards,

Tay Thye Sun


#12
    Your magnetic method for separating natural from synthetic
diamond may not be a fool proof method too.  Why? Only the
large metallic inclusions will be attracted to the magnet and I
found two pieces with large metallic inclusions were able to do
that. 

In fact, Hanneman sells a superpowerful little magnet just for
this purpose. He does not suggest that one try to pick up a
diamond with it. What he suggests is that one take a cup of
water, a chip of styrofoam and the magnet to a table top. Float
the chip and place a suspect diamond on the foam. With the
diamond floating on the water, try to influence the diamond with
the magnet. If the diamond is influenced, be assured that it is
synthetic. No magnetic diamonds have been found in nature. If it
is not influenced it is most likely natural. This test is not
absolute. Cleanliness is very important as I have seen
contamination affect it. It is however a very good indicator.

Bruce D. Holmgrain
Maryland’s first JA Certified Master Bench Jeweler
@Bruce_Holmgrain


1-703-627-8580


#13

I believe some natural green diamonds are influenced by a
magnet.

Greg Fisher
Gemsources
Austin, TX.
www.gemsources.com


#14

I know of this method but when you operate a laboratory and want
to prove to your customer that the diamond that he or she is
holding is a synthetic. You need to have a stronger prove than
floating a diamond on a foam or plastic piece and waiting for it
to be attract to your magnet. If you go to a court case over
this thing, would the judge believe it? I think the judge would
prefer to have a more scientific data, i.e. cathodoluminescence,
FTIR or EDX!!!

With best regards,

Tay Thye Sun


#15

Here are the different properties for synthetic diamonds produced by

  1. General Electric.

  2. Sumitomo.

  3. DeBeers.

  4. General Electric.
    -colour : yellow, near colourless and blue.
    -sizes : up to 1 carat.
    -crystal shapes : octahedra modified by a cube or a dodecahedron.
    -fluorescence to LW/UV : inert.
    -phosphorescence : for yellow none, for nearly blue and colourless
    strong yellow.
    -fluorescence X-Rays : for yellow none, for nearly colourless and blue
    strong yellow with a strong phosphorescence.
    -absortion spectrum : no sharp bands.
    -electrically conductive : for yellow none, for nearly colourless and
    blue yes.
    -INCLUSIONS : primary flux inclusions; dust of very fine white
    particles; some small nickel plates; and an obvious colour zoning in
    the yellows.
    -other :they are magnetic; some obvious metal inclusions.

  5. Sumitomo.
    -colour : yellow.
    -sizes : up to 2 carats.
    -crystal shapes : distorted octahedra that has been modified by a cube
    or /and a dodecahedron.
    -fluorescence LW/UV : inert.
    -fluorescence SW/UV : for yellow or green-yellow moderate to strong.
    -phosphorescence : none.
    -fluorescence, X-Rays : weak to moderate ,bluish white.
    -absorption spectrum : no sharp bands.
    -INCLUSIONS : vein-like of colourless areas; some black flux opaque
    material;and graining.
    -other : has a slight attraction to magnet and also obvious metallic
    inclusions.

  6. DeBeers.
    -colour : brownish and greenish-yellow.
    -sizes : crystals of up to 11 carats.
    -crystal shapes : distorted octahedra modified by a cube or a
    dodecahedron.
    -fluorescence LW/UV : none.
    -fluorescence SW/UV : for the yellow none; for the brown-yellow
    moderate to strong yellow; for the green-yellow a weak yellow.
    -phosphorescence : only for the green-yellow a weak yellow.
    -fluorescence X-Rays : for the brown-yellow a moderate dark yellow; for
    the yellow a stronger dark yellow; for the green-yellow a strong yellow
    with a strong phosphorescence.
    -absorption spectrum : no sharp bands.
    -electrically conductive : no.
    -INCLUSIONS : clouds of very small white-like pinpoints; larger
    metallic inclusions; a distintc colour zoning that is aligned with the
    internal graining.

The heat conductivity is just as similar as the one in natural diamonds
, as well are the specific gravity and the refractive index.

Regards,

Francoise.