Featured Possibly a Vauxhall glass brooch?

I have had this brooch since about 1979 - bought for pennies at a jumble sale - and completely forgot about it until finding it by chance a few days ago. Sadly it is a bit the worse for wear with some chips & nibbles and a couple of missing/broken pieces. Looking at it now I'm wondering if it could be Vauxhall glass?
It measures a fraction under 2 inches across. Think the pin may have been replaced at some point. Mid to late 1800s - earlier? Later? Any thoughts would be much appreciated.

 

Vauxhall glass or French jet, might be either. That’s an earlier hinge, so early to mid 19th. Get a soft toothbrush and a bit of vinegar or spray window cleaner on it.

 

Is the glass silvered on the back or not?

 

Oops, I should have cleaned it before taking the photos!
It's quite difficult to see but looking through from the back I think there are traces of silvering on the edges of the glass pieces that overhang the metal backing.

 

Ah, I think you’re right. Vauxhall then and be very very careful how you clean it. Soft brush, then sunshine cloth.

 

I thought French jet is just black Vauxhall glass, how can you tell the difference? Mine have the same construction (backed by metal panel)

 

Thanks for your replies - I had a feeling it was probably VG.
Sadly I'm probably responsible for most of it's damage. Back in the late 70s/early 80s I had quite a collection of old (vintage!) clothes & jewellery bought mainly from jumble sales & second hand shops. When other girls were wearing Laura Ashley I would go out in a beaded 1920s dress or a 1950s ballgown on a Saturday night!. Can't quite believe how carelessly I treated it all - altering dresses(badly) to fit and chucking lovely old jewellery all together in a box so much of it got damaged. I am much more careful nowadays!!

 

VG is often foiled or silvered, unlike French jet.

I wore vintage like mad, just like you. Ma had things that she’d had made in the forties and fifties, loved them, and she had stage clothes. I’ve still got a few, including jewellery.

 

I found two similar pins, damaged, in a "junk" jar recently. Now I need to go look for some foiling, but I suspect just french jet. I never get that lucky.