help with jewelry (mostly brooches)

Hello!
It's been awhile since I posted. I'm thinking of getting into selling jewelry a bit, but really am lacking in knowledge in this area. (and really am excited to learn!) Are we allowed to post photos of jewelry and not just clothing? I'll update this thread with photos if it's ok.

Thanks!

So the first set of brooches I felt were more "interesting" and seemed older than the 2nd bunch which seemed more like costume jewelry (although some of the other interesting ones might be too!)

Notes: The brooch with the blue glass stone in the center might be silver? - I need to clean it.

The brooch with the green center stone is missing all the surrounding stones, it also has some greenish oxidation - does this signify a type of metal? Brass?

The other brass colored item is a belt buckle I think? I says Czechoslovakia and something like Ges Gesch 81. I did a bit of research and found this snipet via etsy: ""Czechoslovakia 81" and "GES GESCH 81". This marking 'Ges Gesch', engraved on jewelry, is short for 'Gesetzlich geschützt,' which means 'proprietary.' This indicates that there is or was German patent protection on some aspect of the jewelry making. That also indicates that the age of this rhinestone buckle is placed between 1938-1945, a time period of which Czechoslovakia was under German occupation." This also has some green oxidation of some sort on areas.

The flower broach with blue stones says LN/25.

Brooch? with the tiny red stone - This one is pretty - It has some engraving along the sides and a pin closure on the back in addition to the stick pin.

The flower brooch was interesting to me because it seems painted/lacquered. Seems newer though?

The little round brass-colored purse? I'm not sure what to call it. I don't know what this is besides a little purse and not sure what you would even put in it.

The beads seem interesting to me because they have oxidation and seem to be tiny brass beads. The larger beads seem handmade and unique and the little black beads are irregular. The colored ones seem to have dichroic type glass? They are shiny in the center.

The crystal necklace I included because I don't have any idea about it - I have about 1o of these in different lengths and styles!

Thank you for any input and hope this isn't too lengthy!