Question on level of ruby treatment

[simplysplendid]

Hi,

Pardon my ignorance, would someone kindly enlighten me on why heat treated rubies with flux will result in different levels of flux remaining in the rubies? Is it by chance or does it have to do with the number of inclusions or severity of inclusions to begin with?

I refer to GRS grading of H(a), H(b), H(c) and H(d). H(a) has less than 0.001ct of residue, H(b) has minor residue, H(c) has residue, H(d) has major residue. Why does this matter if flux is used anyway?

 

[morecarats]

Heating a ruby with a flux is designed to "heal" fractures. Unlike fracture-filling with lead glass, heating with a flux is designed to dissolve the walls of the fracture and fuse the fracture.

The amount of flux residue remaining depends on the size and number of the fractures. The smaller the fractures and the fewer in number, the better. It''s simply a matter of relative quality, and most gem labs take pains to identify the degree of flux healing in their analysis.

 

[chrono]

I agree with MoreCarats. The purpose of the flux is to “melt” the material and have the fracture close up somewhat. Lead glass filling is exactly what it means; filling of the voids or fractures. The more included the stone, the greater the residue of flux healing. Naturally, price will also reflect that. The more heavily treated it is, the less expensive the ruby is.

 

[simplysplendid]

Thanks morecarats and chrono..

H(a) has less than 0.001 carat of flux, that is really really little. Would a cutter or miner use that little flux deliberately to flux fill the ruby? Or would this possibly be a result of left over flux used in the tools for heating tainting the ruby? If it is an intentional or a deliberate effort, how do they measure the amount of flux used at such micro levels?

 

[Indylady]

Date: 1/7/2010 9:31:21 AM
Author: simplysplendid
Thanks morecarats and chrono..

H(a) has less than 0.001 carat of flux, that is really really little. Would a cutter or miner use that little flux deliberately to flux fill the ruby? Or would this possibly be a result of left over flux used in the tools for heating tainting the ruby? If it is an intentional or a deliberate effort, how do they measure the amount of flux used at such micro levels?

Would a cutter or miner use that little flux deliberately to flux fill the ruby? It depends on where the fractures are.

Would this be a result of left over flux used in the tools for heading tainting the ruby? I don''t think so; from what I understand, traditional heat is generally not invasive enough to melt fractures.

Are you in the market for a ruby?

 

[simplysplendid]

Thank you IndyLady..

Most of the heated rubies that I have seen comes with a H(a) grading. Is a H (heat only without flux at all) common in rubies? Or would it be uncommon since most rubies have lots of inclusions and fractures and be more common in sapphires?

 

[haagen_dazs]

do people flux heat treat other sapphires eg blue and pink ?
i notice its more prevalent in rubies

 

[Indylady]

Date: 1/7/2010 8:08:27 PM
Author: simplysplendid
Thank you IndyLady..


Most of the heated rubies that I have seen comes with a H(a) grading. Is a H (heat only without flux at all) common in rubies? Or would it be uncommon since most rubies have lots of inclusions and fractures and be more common in sapphires?

Is it common? Well,if you compare the number of flux healed rubies available today to the number of heated rubies available, yes, heat only rubies are uncommon. However, flux healing is a relatively new phenomenon, and in the grand scheme of gemological history and amongst fine gems, heated gems are not uncommon and untreated rubies are preferred over heated rubies. While there are a few fine specimens of flux healed rubies, most are commercial grade and collectors prefer heated or untreated rubies. As long as the treatment is disclosed and the consumer is paying a fair price, there is nothing "wrong" with a flux healed ruby, and it is a permanent treatment. I''ve also read of flux healed rubies sometimes looking "gluey" under a loupe. Here is an article about flux healing from Pala that is very informative and sometimes funny too. Flux Healing of the Mong Hsu Ruby

 

[chrono]

Date: 1/7/2010 9:06:45 PM
Author: haagen_dazs
do people flux heat treat other sapphires eg blue and pink ?
i notice its more prevalent in rubies

There are far more clean blue and pink sapphires than rubies, hence rubies are more commonly flux healed.