Is this a common rhinestone treatment?

Once again hoping to pick the brains of all you jewelry gurus here ...

Purchased this rhinestone collar/necklace the other day "just because" (I think I may have been bird in another life as I cannot resist most sparkly things). Pretty sure they are what is called champagne-colored - but it might just be the color of the setting that is making me think that.

Not an antique, but it does show some age - the gold has worn from the push button clasp and from part of the underside/back of the piece. No identifying marks on the piece ... but it looks as if some effort was put into ensuring that the stones stayed "safe" (explained below).

While looking it over to make sure all stones were there and secure, I noticed that every edge stone has had their exposed edge portion protected by a thick metallic-colored substance that looks like the same stuff that was used under each stone like foiling (not sure that I'm using the correct terms). There are even two "corner" stones on each side of the clasp where the two adjacent edges are protected - all the other edge stones only have the one outside edge done.

Has anyone seen this treatment before? Is there a name for it? I've tried to Google rhinestone edge treatments ... but haven't had any luck so far.

I'm assuming that the wide part with the clasp is what goes in the front ... correct?

Going to try to vacuum the dust from it ... is there a safe way to more thoroughly clean the surface of the rhinestones without risking ruining them?

edge stones ...

close up or corner stone (on right)

regular stones in center of piece - no edge ones

view of entire necklace and, finally, the back shot too

 

I don't think that's there for protection....only to enhance the color ...and yes the clasp side is worn in front.

 

And reflect light back in a prettier, more clear way than the base metal would

 

Thanks for your input, komo. It may be this coating on the back of the stones that make them a hard to describe color... but it is thick and clearly extends up and over the girdle of the exposed side of the edge stones ... if it were purely decorative and not functional, wouldn't it be on all the stones and not just the edge ones?

P.S. - thanks for confirming which is the front of this (although ... with the right dress [which I don't have] and my hair worn up ... I think it might also be interesting if worn with the clasp in the back)

Is this a better photo showing how it only comes out and up over the girdle of the stones at the edge?

 

Thanks bluemoon ... this stuff is similar to what is on the back of a foiled rhinestone, but it is thicker than I've ever come across before ... here is a side view ...

 

looks like it's painted on......but yes or no...liberally applied ..to be sure !