Star sapphire information?

[velouriaL]

I'd love to see this set by Leon, but he told me he didn't like it... didn't explain why, of course, just mentioned a "better" non-star sapphire cab he had in stock...:/

ETA: I firmly Leon's statement had more to do with him than the stone. I'd still have bought in a heartbeat if I weren't a starving phd student!

 

[VapidLapid]

I found these too and thought you might like to have them all collected here:

[URL='https://www.pricescope.com/community/threads/my-grandmas-star-sapphire.94085/']https://www.pricescope.com/community/threads/my-grandmas-star-sapphire.94085/[/URL]

[URL='https://www.pricescope.com/community/threads/my-heirloom-star-sapphire.92662/']https://www.pricescope.com/community/threads/my-heirloom-star-sapphire.92662/[/URL]


This one I found on page 1 of colored e-ring thread. From before my time so I dont know anything about it.


and This one on page 44 same thread

[ edited Ps admin - links are fixed]
Since the new search wasnt working I looked at every page of colored ering eyecandy to collect these

 

[VapidLapid]

[URL='https://www.pricescope.com/community/threads/star-sapphire-e-ring.117986/?hilit=star%20ruby']https://www.pricescope.com/community/threads/star-sapphire-e-ring.117986/?hilit=star%20ruby[/URL]

Now I am confused. Are Kiwi725 and RubyCharm the same person?

 

[MakingTheGrade]

Wow Veloria, I can't believe Leon said that! Yeesh.
Any photos of this mermaid princess ring? I think rose gold would be a nice complement too.

Thanks Vapid! Cab gems definitely aren't as popular as their faceted counterparts, but I think they can be interesting!

 

[iLander]

Google Bulgari, they've been doing primarily cabs jewelry for decades. VERY high end stuff, maybe something will inspire you.

I'm going to start a thread about star sapphire treatments, since I've seen some in this thread (not the violet on in question) that look heavily treated, and frankly, fake.

 

[Lee Little]

Making the Grade,

I think it's amazing to find a natural (not those weird fake ebay ones ) star sapphire in a translucent body. I think the medium purple is pretty cool, too. I don't see any gray, myself, and I think it's worth ordering and seeing it in RL. Worst case, it's a few bucks and a trip to the PO to return it. But I don't think you'll want to . . .

I'm sorry, it's gorgeous. If I could have talked him into a discount, it would be mine already!

Here's a question for everybody: Does a star mean it is definitely unheated?

Great question!
We used to think that a star meant no heat so when they filled them with leaded glass we scratched our heads. Turns out that low heat only dissolves some of the rutile and often makes a star sharper as the base becomes more translucent. Leaded glass only requires low heat, not enough to dissolve the star but actually to make it look better. Of course the leaded glass stars are best not in a ring but they are more durable than a leaded glass faceted stone.
Now in Burma they heat almost all stars at low heat. No leaded glass there but simply traditional low heat. This only started when the leaded glass was introduced and they figured out a little heat could benefit them. Still a lot of unheated ones in the market and the low heat is generally impossible for a lab to detect as it could have easily happened in the Earth as well. Best regards, Lee

 

[MakingTheGrade]

Thanks Lee, very educational! And a little worrisome, sigh, I guess nothing escapes treatment these days.

I was wondering for those of you with cab stones, do you think they face up smaller for their size compared to faceted stones? I'm looking at various sites and google for cab ring inspirations, and the cabs are all at least 10mm. I'm wondering if I should lean more towards bezels just to give the stone a size boost.

 

[velouriaL]

I think a bezel and/or even a delicate halo would look GREAT. Or even something like the wavy under-halo on Chrono's spess reset.

In answer to your question on the other thread, there is no picture of the "mermaid princess" ring, just a vision in my head. There is something about that stone that really reminds me of beautiful deep sea footage of translucent jelly fish. Depending on the color IRL, I think rose gold or icy platinum would look awesome.

I am sooo jealous of everyone's gorgeous cabs. I really wish RubyCharm's VanCraeynest ruby star were still up. I tried tracking that thread down so many times... I really need someone to do a gorgeous cab e-ring so I can live vicariously through them!

 

[VapidLapid]

velouriaL, is this the ring? so far all I can find is this drawing.

 

[VapidLapid]

Well in my search for rubycharm's ring I have found that rubycharm's name was changed to kiwi725. Also there was a link to a thread of her ring that she put in a post in this thread
https://www.pricescope.com/community/threads/star-sapphire-e-ring.117986/#post-2038751#p2038751/

But that entire thread about her ring must have been removed because all i get when I click the link is a message saying I am not authorized to see this thread

 

[MakingTheGrade]

Yeah, I tried a link like that before too but never found it! I wonder why the thread was taken down

 

[Lee Little]

Hi Making the Grade,
Cabs usually do need to be bigger than faceted stones since they are almost all about color while a faceted stone is also about light return. The bezel actually covers more of the stone than say a prong setting but provides a much more durable mount. A cab with a high dome can easily compensate for any material hidden by the bezel. Best regards, Lee

 

[Richard M.]

Now in Burma they heat almost all stars at low heat. No leaded glass there but simply traditional low heat. This only started when the leaded glass was introduced and they figured out a little heat could benefit them. Still a lot of unheated ones in the market and the low heat is generally impossible for a lab to detect as it could have easily happened in the Earth as well. Best regards, Lee

I roughed out and oriented this star sapphire yesterday from some African material I'd had heat treated to see if clarity and color could be improved. I just put a "lick and a promise" finish on it and the star sharpness will be greatly improved when I complete the polishing job. I was very surprised to discover the stone had more obvious silk after heating than before! The crystal growth-zoning and spotty color distribution will result in a mediocre-quality stone even after it's completely finished. But I was frankly surprised at this outcome and your post helps explain it. My notes indicate this stone was heated to 1600 C. in air.

 

[Lee Little]

Hi Richard,
Nice work. That will be a good looking stone with no leaded glass when you are done.
I am surprised at how high the temp was, 1600c is high heat, low is usually under 1000c. The treater must have decided on higher heat for that particular material due to the density of the silk and the star is still there so he knew what he was doing.
I am guessing that the color lightened, correct? Keep up the good work, nice to see it in progress, best regards, Lee

 

[Richard M.]

Hi Richard,
Nice work. That will be a good looking stone with no leaded glass when you are done.
I am surprised at how high the temp was, 1600c is high heat, low is usually under 1000c. The treater must have decided on higher heat for that particular material due to the density of the silk and the star is still there so he knew what he was doing.
I am guessing that the color lightened, correct? Keep up the good work, nice to see it in progress, best regards, Lee

Actually the heater followed my instructions on temperature, based on Ted Themelis's published tests with sapphire from that location. The stone appeared to be fine royal blue with very slight growth zoning when I started cutting but the outer color ground away to reveal the color/structure as pictured. I don't know if that would have happened if it hadn't been heated. I have a few more pieces of rough to work with, some unheated, so maybe I'll be able to figure it out.

Richard M. (Rick Martin)

 

[Lee Little]

Hi Rick,
Ah, that explains it then, using Ted's information is the surest way to get it right. If anybody would know, it would be him. That guy has an amazing collection of information from virtually every known mine on the planet. I was thoroughly impressed not only with Ted's vast knowledge of treatments but also of his in depth gemological and geographical understandings as well. When Ted talks, I listen. Best regards, Lee

 

[MakingTheGrade]

Hi Richard!

Do you happen to have before and after pics of that star sapphire? It looks like it will make a nice gem!

 

[Richard M.]

MTG, I almost never photograph rough prior to cutting but in this case I did by chance. I wanted a record of its appearance prior to heating. The rough is pictured at the left in this image. The stars in corundum play hide-and-seek as you're cutting and the trick is to end up with a nicely-centered star in the largest possible symmetrical stone. That can take a little doing. The stone will finish out between 7 x 9 and 6 x 8 mm.

Richard M. (Rick Martin)

 

[Michael_E]

The crystal growth-zoning and spotty color distribution will result in a mediocre-quality stone even after it's completely finished.

Well mediocre or not I think that's really turned out nicely. I just love being able to see that pronounced hexagonal zoning in the silk. It's almost modern art...except that it's probably millions of years old.

 

[Richard M.]

Michael, thanks for your comments. I like the growth-zoning lines a lot too but maybe our tastes are sort've "inside baseball." My comment was based on normal commercial grading but I imagine there are many PriceScopers who feel the same way, especially since hexagonal growth lines are absolute proof of natural origin and are "artsy" in and of themselves. The deposits date from the Cenozoic, from 60 to 300 million years ago.

Richard M. (Rick Martin)

 

[chrono]

Not all inclusions are "bad" or ugly and this is one example where the inclusion is majorly cool. It is a great stone showing the natural growth lines.

 

[MakingTheGrade]

Not all inclusions are "bad" or ugly and this is one example where the inclusion is majorly cool. It is a great stone showing the natural growth lines.

Agreed! I for one love interesting inclusions.
You could argue that if it weren't for inclusions, there would be no star at all!

 

[Largosmom]

I really like the inclusions too...cool pattern that reveals a lot about the crystal structure of the stone, hope to see it finished!

 

[MakingTheGrade]

New question:

Why do star sapphire cabs have an unpolished "butt" (and for the love of gems, what do you call that part!) ? Many other cabs don't have a girdle line or a "butt", but rather are just flat in the back, so why do stars have a booty?