Inclusions in unheated “Velvet Blue” sapphire: Please help me understand what I’m seeing

[Dr_Diesel]

This is a 1.26 carat unheated "velvet blue" sapphire from Sri Lanka that was certified by London Gem Lab (LGL) in Sri Lanka

While it does have some rutile silk, it seems that the velvety appearance is due to more than just that. I’m seeing what appears to be a very consistent fingerprint inclusion running throughout the entire crystal (not just a single plane) as well as the number of pinpoint inclusions.

Does anybody understand what we’re looking at? Please tag experts like @fredflintstone @Karl_K @PrecisionGem and anyone else who you think might be able to offer some insight.

I’ve included a couple of normal photos, as well as photos taken with the assistance of a 4x macro lens shining through a 10 X Loop and a 2x magnification boost from my phone.

I think that means that the total magnification is somewhere around 80x? I’m not sure how that math works. Anyway, I digress:

 

[Dr_Diesel]

Here are some videos in case you’re curious what it looks like to the naked eye:

https://imgur.com/a/fLEPOKi

 

[MMtwo]

Beautiful stone.

 

[Dr_Diesel]

Here are some pavilion images so that you can see that, unlike a typical fingerprint or healed fracture (which usually occur in a single plane) these inclusions occur throughout the entire crystal and spread in all three directions:

 

[Avondale]

I'll try tagging @Autumn in New England because I recall she was studying at the GIA. Although, I haven't seen her in a while... But if she sees this, maybe she'll be able to offer some insight.

This is fascinating. It looks like a fingerprint, but the inclusions are spread all throughout the crystal. Wonder what level and grade of clarity that gives the stone. But no wonder it's so silky and glowy, just imagine what's happening to the light inside that crystal, it's bopping and bouncing all over the place.

 

[VividRed]

I would get it because of the amazing fingerprint inclusion, I love watching gems under a loupe and this one would keep me busy for hours. Who am I kidding…years

 

[Dr_Diesel]

I would get it because of the amazing fingerprint inclusion, I love watching gems under a loupe and this one would keep me busy for hours. Who am I kidding…years

It’s definitely piqued my curiosity! I’ve never seen anything like it, including in the Lotus and GIT databases.

I’m wondering if it may be some combination of primary and secondary cavities… which has me wondering, what kind of conditions might’ve caused such an inclusion to occur throughout an entire crystal instead of just a single plane.

You can see from this close-up pavilion photo how the cutting wheel opened up some of the liquid inclusions:



I have a friend who is studying at the GIA send some of the photos to his instructor, so maybe we’ll get some information there.

Such a fascinating phenomenon!

 

[Lisa Loves Shiny]

It has such a beautiful color. Interesting how the stone looks so clear from your pics and how there's a whole nother world going on there under the microscope.

 

[Dr_Diesel]

It has such a beautiful color. Interesting how the stone looks so clear from your pics and how there's a whole nother world going on there under the microscope.

It’s all of those microscopic conclusions that scatter light and give it the “velvet” appearance

 

[glitterata]

It looks like the pelt of a brilliant blue panther.

Tagging @LilAlex in case he hasn't seen this yet.

 

[Dr_Diesel]

It looks like the pelt of a brilliant blue panther.

Tagging @LilAlex in case he hasn't seen this yet.

I love this analogy! Thank you for the lovely imagery!

 

[Dr_Diesel]

It has such a beautiful color. Interesting how the stone looks so clear from your pics and how there's a whole nother world going on there under the microscope.

Also, part of the reason that the inclusions are so clear in the microscopic photos is because the stone is backlit. When I attempted to photograph it with front lighting (an illuminated loupe with its own ring light), the inclusions were far more difficult to see.

 

[Begonia]

Some day, when I get some funds, I'm gonna ask for your help sourcing a stone doc.

 

[Dr_Diesel]

Some day, when I get some funds, I'm gonna ask for your help sourcing a stone doc.

I'm not sure how the rules work, but I am willing to share the contact info for the Sri Lankan broker who sourced this stone. Am I allowed to do that @Ella ?

 

[Lisa Loves Shiny]

Also, part of the reason that the inclusions are so clear in the microscopic photos is because the stone is backlit. When I attempted to photograph it with front lighting (an illuminated loupe with its own ring light), the inclusions were far more difficult to see.

Very informative, thank you. You must be very happy with this gorgeous stone in your collection.

 

[Begonia]

I'm not sure how the rules work, but I am willing to share the contact info for the Sri Lankan broker who sourced this stone. Am I allowed to do that @Ella ?

S'okay. Timing isn't right doc.

 

[HockeyMama]

I'm not sure how the rules work, but I am willing to share the contact info for the Sri Lankan broker who sourced this stone. Am I allowed to do that @Ella ?

I would love to know, if allowed? I think somewhere there’s a thread of recommended vendors so I think it’s ok?

 

[Dr_Diesel]

I would love to know, if allowed? I think somewhere there’s a thread of recommended vendors so I think it’s ok?

I agree, it seems like it should be alright, but we'll wait for Ella to weigh in to be sure. If she gives the okay, I'll share the details then.

 

[LilAlex]

I think those regularly-spaced cavities are an artifact of the 3D printing process.

I did not know that fingerprints are typically confined to a plane? I def have a lower-tier sapphire from one of the PS-recommended cutters that has huge fingerprints not that are confined to a single plane. Fortunately, they are not under the table and mostly hidden by a busy Portuguese-cut pavilion -- and thereby invisible in vendor photos.

I have not had great luck with "velvety" sapphire. The one we have with a true full-sun glow must have silk too fine to discern -- it just looks clean.

 

[ItsMainelyYou]

Some day, when I get some funds, I'm gonna ask for your help sourcing a stone doc.

Me too, meeee too! I just need some actual dollars to rub together.

 

[Dr_Diesel]

I think those regularly-spaced cavities are an artifact of the 3D printing process.

I did not know that fingerprints are typically confined to a plane? I def have a lower-tier sapphire from one of the PS-recommended cutters that has huge fingerprints not that are confined to a single plane. Fortunately, they are not under the table and mostly hidden by a busy Portuguese-cut pavilion -- and thereby invisible in vendor photos.

I have not had great luck with "velvety" sapphire. The one we have with a true full-sun glow must have silk too fine to discern -- it just looks clean.

This one looks clean to the naked eye as well. The inclusions are barely perceivable even through a loupe. I initially thought they were was rutile silk, but then noticed the orientation wasn't right. and in some places almost looks like dust inside the stone. It required much higher magnification and backlighting to see what is now apparent in the photos.

As for fingerprints being confined to a single plane, that's all I've ever seen. It also makes sense since most reference books refer to them as healed fractures. Seems like maybe there's more to it though?

I'm going to bring the stone to a local gemologist (hopefully next week) and see if he can offer additional insight.

 

[Dr_Diesel]

I found this in a slide presentation from SSEF on Kashmir sapphires. Apparently velvet isn't entirely about rutile.



vs. current stone:




Not identical, but similar?

 

[Dr_Diesel]

And this one from Gubelin (also Kashmir):

 

[Dr_Diesel]

So, I met with one of the instructors at the GIA in Bangkok, and we looked at it through his microscope.

It turns out that fingerprints are in fact planar, but the stone is unusual because there are multiple overlapping, parallel planes of fingerprints.

Here’s a little eye candy for you, a.k.a. a photo dump:

 

[VividRed]

So, I met with one of the instructors at the GIA in Bangkok, and we looked at it through his microscope.

It turns out that fingerprints are in fact planar, but the stone is unusual because there are multiple overlapping, parallel planes of fingerprints.

Here’s a little eye candy for you, a.k.a. a photo dump:

If you ever want to…ehm…trade it for money, do let me know

 

[Avondale]

Apparently velvet isn't entirely about rutile.

Nope, and you need only look at emeralds to find confirmation of that theory - their glow is often attributed to inclusions. We associate velvet with silky, from then we make the jump to rutile silk, but it's definitely not the only contributing factor.

Fascinating little gem, that one. You must've had a blast looking at it under a microscope.

 

[ItsMainelyYou]

Really, what else is there to say? I want.