hpht

[danfarnz]

hi there
does anyone knows of a laboratory where i can process stones by HPHT ?
regards daniel.

 

[Garry H (Cut Nut)]

Try the www.diamonds.net news service search and google searches.

I think they will only do it for bulk parcels. Not all stones respond.

 

[danfarnz]

thanks very much for you prompt and kind reply,
if you'll have more info, please send me an e-mail,as i need this service badly, my address ;
[email protected]. thanks again, daniel.

 

[Richard Sherwood]

A friend of mine has a large light brown diamond which he wanted to have HPHT treated. He contacted Bellataire, which is one of the major companies doing HPHT (if not THE major company). I'm not certain how many are capable of doing the treatment, but it's not many.

They said that they didn't treat any other diamonds than their own. They offered to buy the stone from him though, at a better price than he had been offered through his usual channels. (It is a good looking 10+ carat antique cushion cut, and he had been trying to sell it for a year).

I don't know if this policy is the norm for the HPHT companies, but that was his experience.

Does anyone know how many companies other than Bellataire are using the HPHT process? I seem to remember a foreign company doing it as well.

Rich, GG
Sarasota Gemological Laboratory

 

[Rook]

Sorry but; HPHT?

Is that a heat treatment to make the stone more colorless?

 

[Richard Sherwood]

Hi Rook. HPHT stands for High Pressure High Temperature. It only works for certain diamonds, turning some light browns into whiter stones and certain other stones into fancy colors.

It involves the crystal structure and nitrogen content of the diamond. Light brown diamonds often have a "strained" crystal lattice which creates the color. The HPHT treatment "anneals" the stone, relieving the strain and elimating the color.

Pretty cool, huh? When it first came out, it threw a lot of laboratories into a tizzy. About a year was spent researching the process, with techniques of identification being devised. The main producer, Bellataire, was cooperative in submitting stones to the GIA for their research, as well as identifying their stones with a laser inscription on the girdle.

The HPHT diamonds trade at a reasonable discount over their non-treated counterparts, and are developing a market niche of their own.

Rich, GG
Sarasota Gemological Laboratory

 

[danfarnz]

HPHT. bellataire has not exclusivity any more.the orocess is done in few countries,israel,sweden,germany, russia, australia, canada ,usa,irland ,rumors about china.
i'm looking for lab address where i can ship my stones to be processed, bellataire probably does not process for outsiders,thanks,daniel.

 

[diadlr]

We can provide stone analysis for the HPHT process and also process the stone.

 

[Richard Sherwood]

How much does it run?

 

[diadlr]

You can e-mail me at [email protected] or phone me at 613-966-6666 and we can discuss costs and procedures.
Diadlr