Post subject: How To Describe This Ruby? Fissure Filled, Standar Heat Only
Posted: Thu May 04, 2017 2:03 am
Established Member
Joined: Wed Sep 10, 2014 10:54 pm Posts: 43
I'm looking for some direction and what to call this Ruby. As can be seen in the image, there are obvious gas bubbles that have been trapped inside the stone. The report states CE (RF) which according to the website is: Indications of clarity enhancement by heat processing: residues and foreign fillers within fissures and/or cavities. I sent an email to the lab and this is the response I got:
Quote:
By ‘foreign fillers’, we mean unstable glass or borax based silicate mixture which has not been ‘trapped’ by recrystallized corundum. Unlike ‘lead-glass heating’, standard ‘borax-based heating’ requires high temperature and host corundum starts to melt. Thus, fissures are healed with the mixture and often gas bubbles together with recrystallized corundum creating stable ‘residues’. If we recognize those unhealed fissures containing ‘foreign fillers’, we use the code CE or ECE (RF), and if not, (RS). Rubies with healed and unhealed fissures are still the result of ‘normal (borax-based) heating’.
Their clarification ia very poorly worded, but what they seem to mean mean is that it is a lead glass filled stone rather than a borax heated/fluxed stone. The bubbles are a pretty definitive indicator anyway.
Post subject: Re: How To Describe This Ruby? Fissure Filled, Standar Heat
Posted: Thu May 04, 2017 6:00 am
Established Member
Joined: Wed Sep 10, 2014 10:54 pm Posts: 43
Hi Stephen
It is actually the opposite.
They are saying it is not lead glass used for the filler. But instead it is unstable borax based glass (silicate) that has not been trapped by recrystallising corundum.
Borax based glass is often seen in Ruby and Sapphire as a by product of standard heating, but in that case the borax is trapped inside the gem by recrystalised corundum. In the eyes of GRS they define that as:
H(b) Enhanced by heat – minor residues are present (within fissures only)
So in this case, the borax glass filling is extreme and is not trapped by corundum making it unstable
So I am inclined to call it 'fissure/fracture filled' Ruby stating that the filler is unstable glass or borax based siliocate
The wording is twisty but I am sticking with my interpretation. Regardless, with bubbles that big you have significant voids filled with glass, possibly even entire seams, which is typical of lead glass filling rather than just heating in borax as I understand it. As Barbra said these stones have so much filler that they have come to be regarded more as a composite like a doublet than a single treated stone. They had some market value for a while as a cheap and accessible alternative but once their instability and fragility (and the sheer volume of filler involved in some cases) became known the value plummeted.
Post subject: Re: How To Describe This Ruby? Fissure Filled, Standar Heat
Posted: Wed May 17, 2017 7:05 am
Gold Member
Joined: Wed Jan 23, 2013 5:29 pm Posts: 1047 Location: Paris
Wow, the last pictures of this link are impressive ! Ruby jigsaw !
Question, does anybody know if the glass filling in these stones is sensitive to chemical solvants like acetone ? Or do they react to acids only ? Thanks !
Post subject: Re: How To Describe This Ruby? Fissure Filled, Standar Heat
Posted: Sun May 21, 2017 12:49 pm
Valued Contributor
Joined: Sat Nov 05, 2016 11:29 am Posts: 142
Isi,
Acetone should have no effect on glass. Non-reactive organic solvents should be fine. I would think that in order to damage the glass, you'd have to digest it in acids, or have prolonged exposure to concentrated alkaline hydroxides. Glass is fairly inert. I did once have an issue with a cleaning solvent eating the mold release agent out of a glass storage container. It wasn't a standard hydrocarbon. It was halogenated, and I think that's where the issue came from. You couldn't see any damage to the glass. If you used the solvent, and then dried the glass, it wasn't an issue. Exposure time had a part in this. If you clean a stone and allow it to dry fairly quickly, you shouldn't have any problems.
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