Featured Layered glass Shamrock Brooch

I found this unusual little brooch and have a few questions please. The gems are made of clear glass layered with black glass around the outside. It’s not paint, it is black glass. It looks damaged but it’s just reflections and possibly some wear to the foil backs?
Is this likely Victorian? It’s got a fairly long pin so earlier rather than later?
Would it be considered mourning jewellery?
c1” across.
Thanks for looking

 

I've never see one like it. Victorian for certain. The stones may have been painted all black at some point. Looks pretty cool as it is.

 

This is so high Victorian - the whole thing of black being massively fashionable after Bertie died. Not neccessarily mourning, it was the thing to wear black because Victoria did. Cased glass. Might be as early as the 1860s.

 

Cased glass! That was the term I was searching for!
Thanks OBB

 

...& by the looks of the piece, it hasn't been cleaned since 1861.

 

Most of my collection is bent or broken, merely dirty is unusual! I’d love to give it a scrub but I’d be worried water will get behind those gems. I’ll shine up the back and see what I can do with the front

 

Good brush with old toohbrush first. Vinegar on a cotton bud on the back, give it several goes. The Sunshine it. I'd do the front with window cleaner spray, use a cotton bud if worried.

 

Had to look up cased glass. 'nother to add to my 'antiquers term" list