Red Sapphire not Be treated

[hotroxjeweler]

I'm a GIA Graduate Gemologist with several years under my belt. It's my first week at a new job and my boss - a diamond expert with decades of experience - is telling me that a "red sapphire" ring in our showroom is a natural (not beryllium treated) stone. He claims it is a sapphire that derives its color from a mineral that is different from a ruby. I was always taught that the depth of color determined whether a sapphire should be called a ruby, not the origin of the color or the mine. This stone is a saturated red with brown undertones, much like a garnet.

Any thoughts?

 

[cm366]

Hi HotRox!

Far as I know, it's all corundum, and anything red enough to deserve the word is ruby... but there are much more educated opinions out there!

 

[T L]

I'm a GIA Graduate Gemologist with several years under my belt. It's my first week at a new job and my boss - a diamond expert with decades of experience - is telling me that a "red sapphire" ring in our showroom is a natural (not beryllium treated) stone. He claims it is a sapphire that derives its color from a mineral that is different from a ruby. I was always taught that the depth of color determined whether a sapphire should be called a ruby, not the origin of the color or the mine. This stone is a saturated red with brown undertones, much like a garnet.

Any thoughts?

Chromium gives corundum it red hues and the depth of red color are what define it as a ruby or not. Pink is just a lighter tone of red, and therefore, a more pink form of corundum would be a "pink sapphire." A stone cannot be a "saturated red with brown undertones." It is either saturated red, or it has some brown in it. If it looks like a garnet, then it is probably not a saturated red at all, and probably should not be called a ruby.

It has been my experience in dealing with many gemologists and/or jewelers, that they make their whole careers about diamonds, and therefore, they don't really know as much about colored stones as a result. I knew a jeweler that thought citrine and topaz were the same exact gem, and he sold jewelry for 30 years. Not saying that is the case with your boss, but just letting you know that experience in the jewelry business is not necessarily a good indicator of experience with colored gems.

http://www.bwsmigel.info/GEOL.115.ESSAYS/Gemology.ruby.html

In the end, ruby is just a marketing name, and many unscrupulous sellers use it to make an otherwise ordinary gem seem special, and higher priced. I prefer red and pink corundum, but that's me. As with any form of red and pink corundum, always ignore the marketing name of ruby and evaluate the saturation of color for yourself, and fluorescence (a good ruby or pink sapphire will fluoresce). It is always important to have a reputable lab report delineating all possible treatment on any form of corundum as well, especially if you are investing significant money or sentimentality in it.

 

[Pandora II]

Is it definitely a corundum for starters?

The rubies from Thailand often look brownish - they contain a fair whack of iron as well as the chromium. Iron is a killer to fluorescence so they don't have the glowyness about them that many rubies from other sources can have.

In any case, the definition of a ruby is a red corundum - what makes a corundum red rather than pink depends mainly on whether you are the buyer or the seller...

 

[T L]

Is it definitely a corundum for starters?

The rubies from Thailand often look brownish - they contain a fair whack of iron as well as the chromium. Iron is a killer to fluorescence so they don't have the glowyness about them that many rubies from other sources can have.

In any case, the definition of a ruby is a red corundum - what makes a corundum red rather than pink depends mainly on whether you are the buyer or the seller...

Ditto, and iron also kills fluorescence.

 

[Pandora II]

Is it definitely a corundum for starters?

The rubies from Thailand often look brownish - they contain a fair whack of iron as well as the chromium. Iron is a killer to fluorescence so they don't have the glowyness about them that many rubies from other sources can have.

In any case, the definition of a ruby is a red corundum - what makes a corundum red rather than pink depends mainly on whether you are the buyer or the seller...

Ditto, and iron also kills fluorescence.

That's what I wrote...

 

[LD]

So just to summarise:-

1. If it's red and corundum - it's ruby.
2. If it has a different chemical composition as your boss says, then it's not a ruby or sapphire - how does he know about the chemical composition unless this has been tested by a lab (is he using the RI or something else to make that statement?).
3. How does he know this hasn't been BE diffused? It's difficult for people to tell unless they see a lot of coloured gemstone material, have experience with it AND know what to look for AND even then, really only a lab report will be conclusive!
4. BE diffused sapphires can look red (and are typically sold as rubies) some have wonderful clarity and others don't and can look brownish.
5. If it does have a different chemical composition from corundum then it's probably a garnet, tourmmaline or another red/brown gemstone. The RI and SG would help.

The fact your boss is calling this a "red sapphire" is a warning sign that tells me that he really doesn't know much about coloured gemstones (sorry - don't mean to be rude saying that). As TL says, often jewellers branch out from diamonds into coloured gemstone world but the two are completely different and it takes a bit of learning!

 

[T L]

Is it definitely a corundum for starters?

The rubies from Thailand often look brownish - they contain a fair whack of iron as well as the chromium. Iron is a killer to fluorescence so they don't have the glowyness about them that many rubies from other sources can have.

In any case, the definition of a ruby is a red corundum - what makes a corundum red rather than pink depends mainly on whether you are the buyer or the seller...

Ditto, and iron also kills fluorescence.

That's what I wrote...

Sorry Pandora, tired eyes today.

 

[chrono]

I am puzzled together with everyone else and share the same opinion on what is a ruby and isn't. Just because someone is a diamond expert, it doesn't necessarily mean that he/she is well versed in coloured gemstones.

If it isn't coloured by chromium, then it is coloured by iron.
Is he skilled enough that he can detect the signs on (non) BE diffusion under high magnification?

 

[mastercutgems]

Hello All

I think everyone on here is rather well versed in rubies and colored gems in general...

One question and I may be missing it as i will miss some things once in a while... LOL

Has the gem been sent to an accredited lab like GIA, AGL, old AGTA, or Geublen ???

If not I would say that is where I think the owner of the gem would want to start as the report will give the gem much more credibility than opinions from independent people like us; even GG people do not have (most of the time) the equipment to test for Be and other new treatments...

I know all I can do on corundum is, do a digital spectrum analysis and check to see if key elements are present for that color in the said mineral, do the RI, check for dichroism,birefringence, and do my 100x under the microscope; other than that I have to turn it over to people with much deeper pockets for testing equipment...

But I am like the rest; if the predominant color is RED, and it is corundum; without any Be treatment... I call it a ruby ???

Just my opinion and nothing meant to harm or criticize any one's opinion...

Most respectfully;

Dana