This is a remarkable antique evening bag.  It has a silver-colored metal frame and double chain; the body is silk velvet, and it's lined in silk with two compartments.  The look is very Edwardian.  I was unable to find a marking on the silver frame but it responded well to a light silver polishing, so it may be at least silver-plated.  Both sides of the frame are identical and have amazing detail, with circular sort of nail-head designs alternating with incised stars and leaves.  The plates just above the hinges on both sides are larger rectangles with intricate designs too.  The frame is curved and a double chain is attached, with the two chains linked together at the top.  The body is made of gathered velvet in inky dark black, and I wish you could feel it: this is high-grade silk velvet, very soft and cushy.  

At the center top there's a button opening mechanism.  It needs a little help opening, but closes tightly again.  The bag is lined in a blue/grey silk, carefully gathered by hand at the top, and please check the photos closely: there's a hinge mechanism that swings to open either of two compartments in the interior!  I took quite a lot of photos of this because the detail is so remarkable - even the pretty stitching that attaches the velvet to the frame.

This is in excellent antique condition with no major issues except that the top opening mechanism is a bit stiff.  I wish I could date this more exactly; stylistically it has elements of Eastlake style but also could be early Art Deco.  What is clear is that this is a very elegant evening bag for your collection.