Synthetic diamond ID

Hi Jess,

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.

  1. 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.
    -electrically conductive : no.
    -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.

  2. 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.

I am hoping to provide you next week with info on detection
about the the method on Chemical Vapour Deposition (CVD).

I hope this does answer some of your question. Francoise.

Add to De Beers colors above type IIb blues, and Ib?/IIa
colorless (G-J) Spectrophotometry of DeBeers Synthetics shown at
http://www.gis.net/~adamas/debee rs.html

Marty Haske

Adamas Advantage Software: for Gemology, Mineralogy, Inventory
SAS2000 Spectrophotometer Analysis System For Diamond Color Grading,
Diamond Synthetic And Treatment Detection, And General Gemstone ID
Software Demos And Grading Issues at http://www.gis.net/~adamas/
Email Martin Haske mailto:@Martin_Haske for more

Francoise:

Let’s see . . . . merci, merci, et remerci . . . . have I got
that right? Can’t thank you enough for this I would
also be interested to know where such info comes from. I guess I
need to subscribe to whatever magazines or publications carry
this (“Gems and Gemology”?). I hope I will be able to post a
little more extensively later. I am trying to close a real
estate deal this week. Thanks again.

A propos of the above, has anyone seen synthetic diamonds in the
market?