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SSEF & Gübelin standard for rubies and sapphires

Arcadian

Ideal_Rock
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http://www.gubelin.com/en/gemmology/news/switzerlands-ssef-and-guebelin-gem-lab-agree-to-harmonise-pigeon-blood-red-and-royal-blue-standards

I couldn't post the entire title as I wanted due to constraints, this is a seriously narrow definition! good, not good? please read and comment below!


SSEF & Gübelin standard for “pigeon blood red” rubies and “royal blue” sapphires:


1) Colour criteria:

For a ruby or sapphire to qualify for the term “pigeon blood red” or “royal blue”, respectively, the colour has to be an intense, saturated and homogeneous red or blue. The exact ranges of hue, saturation and tone are defined by sets of masterstones. A comparison of the independently created sets held by both laboratories, Gübelin and SSEF, has shown that they are very consistent.

“Pigeon blood red” is best described as a red colour, with no apparent colour modifiers (such as blue or brown). A minute purplish tint is acceptable. The body colour of pigeon blood red rubies is complemented by a strong fluorescence when exposed to ultraviolet light. This fluorescence is caused by high chromium content combined with low iron content, and results in the distinct "inner glow" coveted by ruby connoisseurs.

Historically, the term “pigeon blood red” was introduced for rubies which formed in marbles of the Mogok Gemstone Tract in Burma (Myanmar), and which are characterised by a very low iron concentration. With the discovery of additional ruby deposits in marbles in Burma, such as at Mong Hsu, and in other countries, this term is no longer restricted to rubies from the Mogok region. Nonetheless, most rubies from places other than Burma contain higher concentrations of iron that suppress fluorescence, and consequently do not comply with the labs’ criteria.

“Royal blue” is best described as a saturated blue colour, either pure or with a very slight purplish tint. While “royal blue” is a term that was historically coined for the best quality of sapphires originating from the Mogok area in Burma, sapphires from other metamorphic deposits, such as those found in Madagascar and Sri Lanka, may also display the properties required to qualify for the “royal blue” term.


2) Quality criteria:

In terms of quality, these colour terms can only be applied to rubies and sapphires that exhibit fine qualities, and have not undergone any modification of colour and/or clarity.

Any type of treatment (such as heating, fissure filling, etc.) disqualifies them from being described using these colour terms. Furthermore, they must be relatively free of eye-visible or dark inclusions, and they must show a homogeneous colour distribution with vivid internal reflections.

The size of the stones is not considered a criterion, meaning that small rubies and sapphires may qualify for these colour terms.
 

chrono

Super_Ideal_Rock
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Well, it is supposed to be the best of the best, hence very tight requirements to deserve such a name, right?
 

OTL

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I heard that GRS is narrowing their standard for PB as well, it's harder to get a PB name for a ruby lately.
 

Burmesedaze

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This will push the prices upwards as well with fewer meeting the labs' grade.
 

Arcadian

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So can anyone guess if any of the other top tier labs will follow suit?
 

OTL

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Arcadian said:
So can anyone guess if any of the other top tier labs will follow suit?
Some of the labs already have similar rules since this is not new. GIA is very strict on these terms, GRS is starting to narrow the standard as well.
 

Arcadian

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OTL|1478625076|4095242 said:
Arcadian said:
So can anyone guess if any of the other top tier labs will follow suit?
Some of the labs already have similar rules since this is not new. GIA is very strict on these terms, GRS is starting to narrow the standard as well.
GIA does? I knew they were strict in terms of grading but didn't know they had their own terminology. Of course I knew that most labs have an agreement about the term paraiba but not pigeon blood rubies and royal blue sapphires...off to go check their site!
 

OTL

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Arcadian|1478636313|4095337 said:
OTL|1478625076|4095242 said:
Arcadian said:
So can anyone guess if any of the other top tier labs will follow suit?
Some of the labs already have similar rules since this is not new. GIA is very strict on these terms, GRS is starting to narrow the standard as well.
GIA does? I knew they were strict in terms of grading but didn't know they had their own terminology. Of course I knew that most labs have an agreement about the term paraiba but not pigeon blood rubies and royal blue sapphires...off to go check their site!
I've seen GIA certified PB ruby.
Very rare.
 

minousbijoux

Super_Ideal_Rock
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Arcadian|1478636313|4095337 said:
OTL|1478625076|4095242 said:
Arcadian said:
So can anyone guess if any of the other top tier labs will follow suit?
Some of the labs already have similar rules since this is not new. GIA is very strict on these terms, GRS is starting to narrow the standard as well.
GIA does? I knew they were strict in terms of grading but didn't know they had their own terminology. Of course I knew that most labs have an agreement about the term paraiba but not pigeon blood rubies and royal blue sapphires...off to go check their site!
I didn't know this about GIA either, but then again, I don't have any experience sending rubies to GIA.
 
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