Guess the stone!

[fiona00004]

This was sold as star sapphire. I had my doubts because if the 10k setting, the low price for such a perfect looking large stone.

I will bring it to my jeweler to get it looked at.

In the meantime, what stone do you think it is? Plastic? Star quartz? It's a clear stone, and side view shows a less blue color.

I have to say, it's a FUN index ring though!!

 

[natasha-cupcake]

Iolite?

 

[dk168]

It could be a synthetic star Sapphire.

DK

 

[fiona00004]

It could be a synthetic star Sapphire.

DK

Could be, but would a synthetic sapphire be clear? I always thought they would be opaque....

 

[Avondale]

It could be a synthetic star Sapphire.

DK

I was going to say the same. Look for pictures of lindy star sapphire - you'll notice the resemblance at once.

Could be, but would a synthetic sapphire be clear? I always thought they would be opaque....

You posted a second before me. Hmmm... would you say you see unevenness of the colour, some zoning? To my knowledge that's a sure way of determining natural vs synthetic, at least in sapphires.

 

[dk168]

Could be, but would a synthetic sapphire be clear? I always thought they would be opaque....

The side view of the stone does not look clear to me, just pale.

DK

 

[fiona00004]

 

[fiona00004]

I think the back is painted blue. I believe some star quartz are treated like that?

 

[dk168]

It is clearer in this pic I agree, however, not clean water-clear if you know what I mean.

DK

 

[fiona00004]

 

[pokerface]

The photos directly above very clearly show that this is a doublet. The dome part is probably quartz.

 

[fiona00004]

The photos directly above very clearly show that this is a doublet. The dome part is probably quartz.

Yes, I agree. Foilbacked or something to give the stone a blue color. I am banking on star quartz

 

[Dreamer_D]

Very weird whatever it is! I like the setting and the gem looks fun.

 

[stracci2000]

It's gorgeous, whatever it is!

 

[Starstruck8]

It's beautiful and intriguing, whatever it is.

It appears to be a doublet (or have a painted back), a clear dome over a dark blue back. But it is a dome of 'starry' material (e.g. rose quartz, clear star sapphire) over a plain blue back, or is it plain clear material over a 'starry' blue back? (Or something else?) How would you tell?

I have a 'natural doublet', plain clear yellowish sapphire over a starry sapphire base. Its star is not the best, but it has a very cool feature - it reflects the world, upside down, and much magnified compared to the reflection from the dome. In a 'normal' star sapphire, the star centres reflect the lights, upside down, but only slightly magnified from the reflections on the dome. Here's a comparison, using my stone and a detail from @Catmom's magnificent picture here:

I caught a triple star!

Left, my natural doublet, right Catmom's 3-star pic:


The dome reflections are labelled in caps, their corresponding 'star' reflections (or 'world upside down' reflections) in lower case. Note that for the natural doublet, the star reflections are much more widely spaced than the dome reflections, but for the normal star sapphire, they are just a bit more widely spaced.

Looking at your multi-star pics, I'm thinking I'm seeing stars much more widely spaced than lights, suggesting a plain clear dome over a starry base. But there are too many lights to be sure. Maybe you could take a pic with just two lights (e.g. two flashlights) and two stars? Also, is there any sort of 'world upside down' effect in softer lighting?

Of course, all this may be way off-beam!

 

[pokerface]

Yes, I agree. Foilbacked or something to give the stone a blue color. I am banking on star quartz

It's not a star quartz, it is a regular quartz over a a painted star on the base.

 

[fiona00004]

sometimes the star is there, sometimes it isn't. Reflects upside down images.

 

[fiona00004]

 

[Starstruck8]

sometimes the star is there, sometimes it isn't. Reflects upside down images.

Are the upside-down images much magnified compared to the corresponding reflections from the dome surface? They seem to be, but I can't match them up well enough to be sure. You on the spot would be able to check this.

It would be nice to have a multi-star pic like the one left below, but with fewer lights, so that you could be sure which stars went with which dome reflections. I'd like to be able to match them up as I have annotated. This would confirm starry back. But with so many lights I can't be sure.

It's not a star quartz, it is a regular quartz over a a painted star on the base.

I'm not seeing how this could produce multiple stars from multiple lights, as in the pic above left. Wouldn't it always produce a single star?

What could produce multiple stars is regular quartz (or glass or whatever) over a 'starry' base material. This could for example be a layer of synthetic star sapphire. Another possibility is a blue plate with three sets of parallel scratches at angles 120 degrees apart.

The pic above right shows the idea. The scissors blade is blue with parallel scratches. The loupe (sorta...) simulates the dome. The result is a cat's eye at 90 degrees to the scratches. The setup is lit with two flashlights - I've labelled their reflections in the upper surface of the loupe as A and B. (The reflections just below these are from the lower surface of the loupe.) The left flashlight produces the right bright line and vice versa. With three sets of scratches, you could make a star for each flashlight.

What worries me about the 'starry base material' story is that I haven't been able to find examples on the web. So either this isn't a common sort of simulated star sapphire, or I haven't been looking in the right places.

 

[fiona00004]

Yes, I agree with @Starstruck8 ... If there's a star painted base, not sure how then could there be multiple stars as well as moving star when I move the ring around.

@Starstruck8 would this pic help for multiple stars? I will try to get another one too

 

[fiona00004]

So funny, I literally see a reflection of the light fixture on my ceiling in the ring!

 

[fiona00004]

 

[fiona00004]

So funny, I literally see a reflection of the light fixture on my ceiling in the ring!

Image doesn't seem magnified though

 

[fiona00004]

Here a pic of two softer light sources

 

[Starstruck8]

So funny, I literally see a reflection of the light fixture on my ceiling in the ring!

Yes, that's the picture I was looking for. (I'm assuming the reflection of the light fixture on the dome surface is where the arrow is pointing.)


See how the star centres are much more spread out than the direct reflections in the dome? That's the magnification I was talking about.

I'm now pretty sure of the 'starry base' story. There is still the question of what the base actually is - a slice of synthetic star sapphire, a blue plate with three sets of parallel scratches, or something else?

You might be able to look at it with a loupe, either from the side, showing the join with the dome, or from the top. You just might see fine scratches or tiny needles, but I wouldn't count on it.

There also the question of what the dome is - quartz, glass, something else - this would be relevant to durability.

I'm thinking this is about as far as I can go by looking at pictures. I think you will need to show it to an expert in person to take it further. It would be good if someone could find some examples on the net - I haven't found any so far.

 

[fiona00004]

Under the stove fan lights. There are two lights.

 

[Starstruck8]

Under the stove fan lights. There are two lights.

Good! Confirms my previous reply. See how the star centres are much further apart than the dome centres?

 

[fiona00004]

@Starstruck8 could you elaborate on the 'starry base' term? What do you mean exactly?

i plan to take the ring to a certified gemologist this Saturday.

also, would cleaning this ring in an ultrasonic machine damage it?

 

[fiona00004]

Good! Confirms my previous reply. See how the star centres are much further apart than the dome centres?

I totally get what you mean now!! The dome stars much wider apart than the reflection

 

[Starstruck8]

@Starstruck8 could you elaborate on the 'starry base' term? What do you mean exactly?

i plan to take the ring to a certified gemologist this Saturday.

also, would cleaning this ring in an ultrasonic machine damage it?

Well, 'starry base' isn't exactly a standard gemmological term... I just made it up. I mean that the stars are produced by a layer of 'starry' material in the base. 'Starry' material has lots of parallel inclusions or scratches that cause the star (as I outlined in the demo with the scissors blade and the loupe.)

This contrasts with 'normal' star stones, in which the whole body is made of starry material, not just the base.

If the base and dome are glued, then ultrasonic cleaning could force fluid into the join, weakening it.