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Show your Star sapphires and rubies

Dreamer_D

Super_Ideal_Rock
Joined
Dec 16, 2007
Messages
26,342
My only star is my avatar picture. This was a lucky find for me and a 45th birthday present. The ring is very old as you can see from the bezel being worn around the sapphire. The original shank has obviously been replaced but I adore this ring so much. When I was first considering purchasing I did a Google search and found the attached lab report.

77615E45-D060-4757-850E-EDEB08DF158E.jpeg

B09D7B88-AB83-43DF-849E-77E3384CA2DE.jpeg

So pretty. The setting is so perfect.
 

Pumpkin Sparkles

Rough_Rock
Joined
Oct 14, 2021
Messages
72
I didn’t realize they were that rare, I just know I loved them since I was a teenager. Natural once are harder to come by. That’s an amazing goal to have!
 

Dreamer_D

Super_Ideal_Rock
Joined
Dec 16, 2007
Messages
26,342
I didn’t realize they were that rare, I just know I loved them since I was a teenager. Natural once are harder to come by. That’s an amazing goal to have!

I didn’t know they were so rare either until I needed to replace a damaged one through insurance. I read up and learned a lot and turns out that gem suitable star sapphires are very rare indeed! At the same time there is not much demand outside of Asia. So few make it to the N American market. Put it all together and nice quality large specimens can be very hard to find! Antique and vintage seems the way to go, as the primary market is very bare bones. Again, for nice translucent and transparent ones. There are many opaque examples but they are less prized.
 

Starstruck8

Brilliant_Rock
Joined
May 13, 2021
Messages
657
If I’m not mistaken, those lines are the silk and the angle of intersection is what causes the star to form!

Sort of, but not precisely. The rutile needles in the silk cause the star, and the density of the silk is usually (but not always) zoned. But the zoning does not in itself cause the star, nor is it necessary for a star.

The orientation of the star is related to that of the zoning. In a round stone lit and viewed square-on, the orientation of the zoning lines will fall halfway between the rays of the star. Put differently, the zoning lines will be perpendicular to one of the rays. You can see this in your stone:
StarSapphireDemo.jpg

See how the zoning lines are perpendicular to the lower left ray? And they fall between the top left ray and the top right ray. (In oval stones it's not so simple, because the shape of the dome distorts the orientation of the rays.)

The reason? Both orientations are tied to the crystal axes.

Zoning reflects the growth history of the crystal. What we see as lines of zoning are really planes. (You can sometimes see the planes edge-on if you hold a stone at the right angle.) These planes were once the faces of the growing crystal.

The rutile needles too are oriented by the crystal axes. They are formed by exsolution of titanium impurity atoms. At high temperatures the titanium atoms can jump around in the crystal lattice. For energetic reasons, they tend to clump together in long needles with specific orientations in the lattice. As it happens, these orientations are perpendicular to the 3-fold symmetry axis and parallel to the faces. See figures 20 and 21 and nearby text on this page:
https://www.ruby-sapphire.com/index...by-sapphire-inclusions-in-corundum?Itemid=101

In round stones, the rays are perpendicular to the rutile needles, which are parallel to the faces, and hence to the zoning (if present).

Cool fact: In most (not all) black star sapphires, the star is formed by hematite inclusions (not rutile), which are oriented differently. So in round stones, the rays are parallel to the zoning.

She didn’t like the zoning in mine and went on about her uniform opaque ones being superior, I guess to each their own.
Conventional wisdom is that uniformity is a positive but opacity is a negative. Trade ideal is uniform with just the right amount of translucency. But who cares about trade ideal? More to the point, who can afford it? I love my imperfect stones, because their imperfections point to the processes that formed them.
 
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Dreamer_D

Super_Ideal_Rock
Joined
Dec 16, 2007
Messages
26,342
@Starstruck8 i was remembering something about crystal planes… i feel like you can see those too in one of @Pumpkin Sparkles pictures, are they octagonal?
 

Pumpkin Sparkles

Rough_Rock
Joined
Oct 14, 2021
Messages
72
I didn’t know they were so rare either until I needed to replace a damaged one through insurance. I read up and learned a lot and turns out that gem suitable star sapphires are very rare indeed! At the same time there is not much demand outside of Asia. So few market. Put it all together and nice quality large specimens can be very hard to find! Antique and vintage seems the way to go, as the primary market is very bare bones. Again, for nice translucent and transparent ones. There are many opaque examples but they are less prized.

Sort of, but not precisely. The rutile needles in the silk cause the star, and the density of the silk is usually (but not always) zoned. But the zoning does not in itself cause the star, nor is it necessary for a star.

The orientation of the star is related to that of the zoning. In a round stone lit and viewed square-on, the orientation of the zoning lines will fall halfway between the rays of the star. Put differently, the zoning lines will be perpendicular to one of the rays. You can see this in your stone:
StarSapphireDemo.jpg

See how the zoning lines are perpendicular to the lower left ray? And they fall between the top left ray and the top right ray. (In oval stones it's not so simple, because the shape of the dome distorts the orientation of the rays.)

The reason? Both orientations are tied to the crystal axes.

Zoning reflects the growth history of the crystal. What we see as lines of zoning are really planes. (You can sometimes see the planes edge-on if you hold a stone at the right angle.) These planes were once the faces of the growing crystal.

The rutile needles too are oriented by the crystal axes. They are formed by exsolution of titanium impurity atoms. At high temperatures the titanium atoms can jump around in the crystal lattice. For energetic reasons, they tend to clump together in long needles with specific orientations in the lattice. As it happens, these orientations are perpendicular to the 3-fold symmetry axis and parallel to the faces. See figures 20 and 21 and nearby text on this page:
https://www.ruby-sapphire.com/index...by-sapphire-inclusions-in-corundum?Itemid=101

In round stones, the rays are perpendicular to the rutile needles, which are parallel to the faces, and hence to the zoning (if present).

Cool fact: In most (not all) black star sapphires, the star is formed by hematite inclusions (not rutile), which are oriented differently. So in round stones, the rays are parallel to the zoning.


Conventional wisdom is that uniformity is a positive but opacity is a negative. Trade ideal is uniform with just the right amount of translucency. But who cares about trade ideal? More to the point, who can afford it? I love my imperfect stones, because their imperfections point to the processes that formed them.

I love this!

“I love my imperfect stones, because their imperfections point to the processes that formed them.”

I feel the same way except for visible black carbon inclusions on diamonds I can’t get over that one. It triggers my ocd and I won’t get over it no matter how much time I allow myself to try and love it. :cry2:
 

Pumpkin Sparkles

Rough_Rock
Joined
Oct 14, 2021
Messages
72
I didn’t know they were so rare either until I needed to replace a damaged one through insurance. I read up and learned a lot and turns out that gem suitable star sapphires are very rare indeed! At the same time there is not much demand outside of Asia. So few make it to the N American market. Put it all together and nice quality large specimens can be very hard to find! Antique and vintage seems the way to go, as the primary market is very bare bones. Again, for nice translucent and transparent ones. There are many opaque examples but they are less prized.

I will go a cherish my small collection a little more I didn’t know. Thank you so much for sharing your story I’m so happy you ended up with something stunning that suits you well, I love a good jewelry story!
 

Starstruck8

Brilliant_Rock
Joined
May 13, 2021
Messages
657
@Starstruck8 i was remembering something about crystal planes… i feel like you can see those too in one of @Pumpkin Sparkles pictures, are they octagonal?

Do you mean the picture on the left?
Zoning.jpg

I'm pretty sure that's ordinary hexagonal zoning. The foreshortening makes the corner look sharper. You can see this in the picture on the right, which is less foreshortened. I'm pretty sure that if you looked at the zoning square-on, the corner would have the 120-degree angle of a hexagon.

It's very cool. The hexagonal zoning reflects the hexagonal cross-section of the crystal as it grew. It is history crystallized, so to speak. It also suggests that the stone was part of a much bigger crystal, with its central axis located somewhere to the left of the stone in the right picture. This is why zoning is so fascinating.
 

Pumpkin Sparkles

Rough_Rock
Joined
Oct 14, 2021
Messages
72
Do you mean the picture on the left?
Zoning.jpg

I'm pretty sure that's ordinary hexagonal zoning. The foreshortening makes the corner look sharper. You can see this in the picture on the right, which is less foreshortened. I'm pretty sure that if you looked at the zoning square-on, the corner would have the 120-degree angle of a hexagon.

It's very cool. The hexagonal zoning reflects the hexagonal cross-section of the crystal as it grew. It is history crystallized, so to speak. It also suggests that the stone was part of a much bigger crystal, with its central axis located somewhere to the left of the stone in the right picture. This is why zoning is so fascinating.

@Starstruck8
I have a question regarding this topic the wedding set shown in the previously posted pictures has a hexagon inclusion and silk surrounding it (it’s included) but I was taken back by the hexagon right in the middle. Does that mean that this star sapphire I’m speaking of is a complete crystal on its own?
 

Dreamer_D

Super_Ideal_Rock
Joined
Dec 16, 2007
Messages
26,342
Do you mean the picture on the left?
Zoning.jpg

I'm pretty sure that's ordinary hexagonal zoning. The foreshortening makes the corner look sharper. You can see this in the picture on the right, which is less foreshortened. I'm pretty sure that if you looked at the zoning square-on, the corner would have the 120-degree angle of a hexagon.

It's very cool. The hexagonal zoning reflects the hexagonal cross-section of the crystal as it grew. It is history crystallized, so to speak. It also suggests that the stone was part of a much bigger crystal, with its central axis located somewhere to the left of the stone in the right picture. This is why zoning is so fascinating.

Yes I meant hexagonal and thanks for the added explanation. I had seen similar patterns in my previous star sapphire viewed from the bottom.
 

Starstruck8

Brilliant_Rock
Joined
May 13, 2021
Messages
657
@Starstruck8
I have a question regarding this topic the wedding set shown in the previously posted pictures has a hexagon inclusion and silk surrounding it (it’s included) but I was taken back by the hexagon right in the middle. Does that mean that this star sapphire I’m speaking of is a complete crystal on its own?

Do you mean the one top on ring finger?
Wedding.jpg

Yes! I can't make it out from the picture, but a hexagonal 'inclusion' in the centre would have been the core that whole crystal grew from. Again, the 'imperfections' show the history.
 

glitterata

Ideal_Rock
Joined
Apr 17, 2002
Messages
4,471
Did a PSer buy this? Kicking myself for not bidding. I was sure it would go for much more, and it's a man's ring that would be too bulky for my round little fingers--and I would never have been able to bring myself to ruin that beautiful old J.E.C. setting with its inscription. Still, the stone itself! 4.44 ct of unheated glory! I bet it's amazing in person. WHY didn't I bid????


1717736271016.png
1717736302843.png
1717736337415.png
 

fiona00004

Brilliant_Rock
Premium
Joined
Oct 28, 2012
Messages
1,289
Adding my deep pink beauty. Waiting to get it resized. Can't even wear it at all since it is too big..

PXL_20240612_234257481.MP.jpg
 

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fiona00004

Brilliant_Rock
Premium
Joined
Oct 28, 2012
Messages
1,289
Rosa is back from being resized down. I am obsessed with star Sapphires. So magical PXL_20240630_210449564.MP.jpg
 

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RRfromR

Brilliant_Rock
Joined
Nov 5, 2022
Messages
808
Did a PSer buy this? Kicking myself for not bidding. I was sure it would go for much more, and it's a man's ring that would be too bulky for my round little fingers--and I would never have been able to bring myself to ruin that beautiful old J.E.C. setting with its inscription. Still, the stone itself! 4.44 ct of unheated glory! I bet it's amazing in person. WHY didn't I bid????


1717736271016.png
1717736302843.png
1717736337415.png

@glitterata I was looking at that too but also didn't want to destroy the setting.
 

Catmom

Super_Ideal_Rock
Premium
Joined
Apr 6, 2005
Messages
12,654

Starstruck8

Brilliant_Rock
Joined
May 13, 2021
Messages
657
Very Impressive! I'm amazed that you found three star sapphires matching so well in colour and tone. That must have taken some searching. And I love the bright and razor-sharp star in the centre stone.
 

Ionysis

Brilliant_Rock
Joined
Oct 1, 2015
Messages
1,962
Very Impressive! I'm amazed that you found three star sapphires matching so well in colour and tone. That must have taken some searching. And I love the bright and razor-sharp star in the centre stone.

I had one recut to match - it was slightly oval. The cutter did a nice job, didn’t lose any of the star sharpness. I did order several tiny gems though, fortunately the small grey ones aren’t too pricey. But yes it took months - because I wanted really transparent clarity.
 

Catmom

Super_Ideal_Rock
Premium
Joined
Apr 6, 2005
Messages
12,654
Finally got it set.

No diamonds. Just plain white gold. Casual.

I call it my “crown of thorns” ring.

IMG_3982.jpeg
IMG_3985.jpeg IMG_3987.jpeg 3505A3D8-8F62-4951-9133-17A5E105E3C1.jpeg 38BC0950-EA4C-4EFA-9BCF-1779F37477C4.jpeg E8C32077-76EE-48DD-A250-0FA57C037C52.jpeg F42360F4-113D-4247-91BF-418BCAE17F06.jpeg IMG_3980.jpeg

I love it and the dragon claws!
 

Pumpkin Sparkles

Rough_Rock
Joined
Oct 14, 2021
Messages
72
Finally got it set.

No diamonds. Just plain white gold. Casual.

I call it my “crown of thorns” ring.

IMG_3982.jpeg
IMG_3985.jpeg IMG_3987.jpeg 3505A3D8-8F62-4951-9133-17A5E105E3C1.jpeg 38BC0950-EA4C-4EFA-9BCF-1779F37477C4.jpeg E8C32077-76EE-48DD-A250-0FA57C037C52.jpeg F42360F4-113D-4247-91BF-418BCAE17F06.jpeg IMG_3980.jpeg

This is stunning and well thought out! The sapphires are beautiful and well matched, congrats!
 

GardenLady21

Shiny_Rock
Joined
May 24, 2018
Messages
232
Finally got it set.

No diamonds. Just plain white gold. Casual.

I call it my “crown of thorns” ring.

IMG_3982.jpeg
IMG_3985.jpeg IMG_3987.jpeg 3505A3D8-8F62-4951-9133-17A5E105E3C1.jpeg 38BC0950-EA4C-4EFA-9BCF-1779F37477C4.jpeg E8C32077-76EE-48DD-A250-0FA57C037C52.jpeg F42360F4-113D-4247-91BF-418BCAE17F06.jpeg IMG_3980.jpeg

How cool is this ring? The center stone really looks like a crown. Great setting idea!
 
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