how setting affects the color of the stone

[Arkteia]

I have several "glowy" stones and I have noticed that in some cases, "glow" comes with certain sleepiness, inclusions that disperse the light. I shall post a photo of Gene's Lloliondo spessartite that I bought a while ago - people did not comment on it probably because it was included but it was very glowy.

Now bezeled in a beautiful ring by Arturas Gorinas, it lost the glow - I think because bezel limits the access of light to the stone and hence the sleepiness turns into its opposite.

My Namibian is pretty included but very glowy. The way it was set, with an open bezel and an aura, did not affect the access of light, and it performs well and still glows.

That made me wonder if bezeling "sleepy" stones could do more harm than good. Very clean stones, no doubt, tolerate bezeling well and sometimes the color becomes more saturated.

What do you think of it?

It became important because my new spinel is sleepy but glows and I suspect it may have something to do with inclusions dispersing lights in all directions.

We were discussing it in liew of Kashmir sapphires but interestingly, I never saw them being bezeled.

[URL='https://www.pricescope.com/community/threads/arts-ring.151615/']https://www.pricescope.com/community/threads/arts-ring.151615/[/URL]

And hard as I try, i can not find the photo of Gene's unset stone. Could have disappeared during conversion from PS I to PS II. I shall browse my saved photos and find it. But that do you think of my question?

 

[Aoife]

I'll be interested to hear some discussion of this, since this is something I have wondered about myself. Could you repost the photos of the spess both set and unset?

 

[chrono]

Crasru,
I do not know the answer as I did not bezel set my Loliondo, thus, it did not lose its glow. I do know that bezeling a light toned and light saturated stone helps deepen the colour.

 

[Michael_E]

It became important because my new spinel is sleepy but glows and I suspect it may have something to do with inclusions dispersing lights in all directions.

Light in = light out. In the case of stones which glow, they are not only dispersing light in every direction, but the light which reaches your eyes is entering the stone from all directions. Since the crowns of faceted stones are a much lower percentage of the depth of a stone than the pavilion, the crown has much less light entering it from all directions, (most of the light enters the crown from directly in front of it). In a glowing stone, covering up the pavilion is equivalent to drawing a blind over a window on one side of a room, making the stone appear to have less of a glow and be darker. This is one reason that most stones with micro inclusions that are sleepy or glow, are cut as high domed cabochons, since most of the light entering and leaving them is through the crown, (not to mention that pavilion facets have little or nothing to reflect in really sleepy stones).

The one type of sleepy faceted stone which is better set in a bezel is precious opal. In these stones reflections from the pavilion will light up patches of color inside of the stone and the dark background serves to increase the contrast and color in those areas. The picture of the orange opal here shows a nice play of color against the dark shadows between my fingers. When the background gets lighter, that colors play is reduced and the stone takes on a plain sleepy orange appearance...a good reason to bezel set these stones.

 

[Arkteia]

Beautiful opal, Michael! And great explanation! It makes things so much clearer! I like "sleepy" stones because sometimes this "neon"-like effect around them is produced by micro-inclusions. But I shall be very careful with the setting I choose from now on.
Are you a physicist by educaiton?

 

[JewelFreak]

That is so interesting & informative in a few sentences! Thank you, Michael E.

--- Laurie

 

[Michael_E]

Beautiful opal, Michael! And great explanation! It makes things so much clearer! I like "sleepy" stones because sometimes this "neon"-like effect around them is produced by micro-inclusions. But I shall be very careful with the setting I choose from now on.
Are you a physicist by educaiton?

No, I love studying physics, but am by no means a physicist. My education is in mechanical engineering and I spent many years designing industrial machines and structural steel, (still do at times). I started cutting gems about 35 years ago and making settings for them about 25 years ago. Got my GIA gemologist paper about 20 years ago, bought a small shop and ran it for about ten years. I've had most of the same questions asked here, pop up in my own mind at one time or another. As a cutter/metalsmith I just HAD to find the answers to many of these questions and so when you folks ask them I've already got some of the answers tucked away in the recesses of my dusty, creaky cranial cavity. You're lucky that you don't have to watch me try to remember things. There's a long period of drooling, a low guttural "UHHHHH" and then *POP* something flashes, (Google "Patrick" on Sponge Bob and you'll get the idea), and an answer appears and I regurgitate it here. So far I'm doing O.K. about 50% of the time, the rest of the time I can't go back and read what I wrote...just too embarassing.