Whats this weird rainbow stuff on NGC slab?

I picked this slab up the other day for 6 bucks, its a ms 67 1966 SMS dime, but on the front and back of the slab if you wiggle it around in the light there is some weird rainbow stuff, i tryed my best to capture it in a picture:


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Never heard of it and I've never seen anything like it!! Email NGC and see if they have an answer. BTW, have you checked the certification number?

 

Yea, and the weird thing is...NGC values it at 26 dollars, but i got it for 6, ?

 

So are you gonna crack that slab?

 

No, i bought it for size comparison reasons because i wanted to actually compare it to coins like a 1/10 oz Gold AGE and i thought it was neato,

 

Plastics are made with a "plasticizer", which secretes to the surface of the plastic during the life of the plastic, which is usually less than a hundred years. The rainbow effect could just be the plastic taking a visible set after exposure to sunlight (see toy blister bubble browning), or the plasticizer secreting in an uneven manner. Rubber hoses have lots of plasticizer to make the hose flexible during short service life, and hard plastics have minimal amounts.

 

The faint diffraction can result from stress within the plastic. It will vary according to the intensity and "purity" of light striking it. Best diffraction should be from a broad spectrum source, bulb or sunlight. The stress is probably not consequential and most likely from the manufacture of the slab or the sealing process. At the molecular level, you are compressing the molecules on one side and elongating them on the other making a diffraction grating. Quite common with hard transparent plastic. IMO.

Jim

 

My ANACS (new mustard style) slab also exhibits the same kind of rainbow stuff on the front and back at angles. I thought it was just part of the slab...

 

Good picture , pretty sure it's the light reflecting off the plastic .
rzage

 

I've seen it many times. It's nothing really worry about.

 

You have a gold ASE? WOW! That's definitely an error.

ASE, usually stands for American Silver Eagle. I think you meant AGE, American Gold Eagle.

 

Yea my bad...

 

Very common. Seen it plenty o'times here too.


An excellent synopsis Jim :thumb:

 

Should of read all the posts , very good explanation .
rzage

 

I think you have something there - a rainbow slab. Could be worth twices as much as a slab without the rainbow. Then again, it could be trying to tell you something, you know what rainbows signify.

 

Toned cases always bring a premium!

 

Artificially Stress-toned cases~ So now how to tell the AS from the NS. ?

Jim

 

Is this really toning or what...

 

No, just kidding.

If you have a LED flashlight, go into a dark room and shine the light on the slab. If it is a good quality LED, since it
will only emit a small wavelength range of light, you should not see the rainbow.

 

Does this rainbow crap harm the slab, is it mold or PVC or what?