Glow within - spinel

[foxglove]

This may be a silly question but -

What causes the difference between the following two stones (both from SETTGold)? Both are red spinels, but one seem to glow from within meanwhile the other seems "normal".

The "glowy" one is of SI clarity meanwhile the "normal" one is of VS clarity. Is it because the inclusions give the glowy one the sleepy look like what rutile silk does to Kashmire sapphires? Or does it mean that the glowy one has more fluorescence? Or perhaps the vendor just used different lighting conditions when they took the pictures?

fox

 

[foxglove]

Here''s the picture of the glowy one:
http://www.settgold.com/spinel/spinel-51562.php

fox

 

[foxglove]

Here''s a picture of the "normal" one -

fox

 

[widget]

Hi, Fox...

I the most included stone I have is a Ceylon pad...it has a lot of "silk". It is also the one that seems to best capture whatever light is available and "glow it back" at me.

So it''s my guess that it''s the inclusions that contribute to the "glow".

Have you seen these stones in person?

widget

 

[foxglove]

Hi widget,

I''ve only seen the "normal" one in person. I received it in the mail yesterday! It''s really funny - sparkles red flashes in certain lighting conditions. I find that mesmerizing.. now I understand what Raddy was going through when he took his spinel around town to look under different lighting conditions.

I couldn''t help but do the same when I got mine.

I haven''t seen the sleepy glowy one in person though. I really wonder what it would look like.

fox

 

[Richard M.]

Inclusions have nothing to do with what you observe. I think it''s entirely a matter of cut. The "glowy" stone has better pavilion angles and -- at least in this image -- returns light more uniformly to the eye. The other stone shows areas of black extinction caused by light that''s directed away from the crown of the stone in certain areas and at certain angles. Neither stone looks "sleepy" to me but only direct observation could confirm that. From the image the "glowy" stone appears to be a fine example of orangy-red "flame" spinel.

 

[Michael_E]

I''ve just got to pipe up on this thread. What you''re seeing may be a mater of better cut as Richard has said. BUT it may also be a matter of "better" lighting. If you light a stone with one light, then you can only expect light to be returned from one set of ares on the stone. If you flood the stone with bright, diffuse light then you can expect light from far more areas of a stone and will generally not see the "extinction" that Richard is referring to. The Asian sellers of these stones are getting very, very good at taking digital pictures and on higher priced stones they are obviously aware of the higher prices paid for better pictures, (this does not mean that they are better stones). In looking at these two stones, I would bet a donut that if you had both of them in your hand, they would look nearly identical.

When buying these types of stones from pictures I would advise that you look at the depth numbers as well as any side views present. With depth percentages over 55% and a side view that doesn''t look like a flattened flying saucer, you have a better chance of the stone stone looking as good as its image. Remember that all these images are taken with the stone in it''s most favorable light, (or even doctored for color and brightness). Sometimes what you receive may be disappointing due to your expectations that the stone will look like this image ALL the time, and that''s just not possible.

 

[Richard M.]

Date: 8/5/2005 3:00:40 PM
Author: Michael_E
In looking at these two stones, I would bet a donut that if you had both of them in your hand, they would look nearly identical.

I figured you''d be showing up! I''ll take the bet just to keep things sporting. I like chocolate. It could be lighting instead of cut but we''re both just speculating until we can inspect both stones in 3-D. However if you look at the pattern of extinction in the second stone you''ll note it occurs symmetrically and only on certain facet tiers. That suggests to me it''s improper angles/facet placement, not just lighting. But I''m only betting a donut.

 

[DiamondExpert]

I''m hungry - I''ll bite for a red fluorescence contribution

 

[spinel]

I do agree with Gary, it is strong fluorescence macro-photographied under soft light. Or sometimes you pay a ruby for the price of spinel

All the bests,
Spinel

 

[Richard Sherwood]

I''ll see your Hersheys and doughnut, and raise you a Reese''s peanut butter cup.

 

[Richard M.]

But can we all agree inclusions are not the cause? When do we eat??

 

[raddygast]

Is it just me or does that stone (the first one, "glowy") seem absurdly cheap for its apparent "internet appearance"?

Either that thing is heavily included, with surface-reaching fissures (and there does appear to be something near the table, but it could be a trick of the light or just dust), or it is much darker than it appears, and is being flooded with high intensity light from multiple light sources at different angles.

Otherwise, on my screen, that stone looks very close to the ideal colour -- something that would certainly demand a price many orders of magnitude higher.

But I think I'm gonna go in with Mr. Dutton on this one -- it could be red fluorescence that is causing the difference. Or at least contributing to it. I think there's no way that lighting isn't at least *some* part of the equation.

 

[foxglove]

Thanks for all your insight!
But if manipulating lighting a certain way would make a stone appear more favourably.. why wouldn''t the vendor place all stones under such lighting? (Both stones are from the same vendor).

Yes, in vendors that offer side views of the stone I have often seen the "flattened flying saucer" look. Would a stone like this look darker than it appears in real life?

Thanks again. (Now I''m craving a donut)

fox