It’s typical foliage design work from M. Buccellati in the 1930’s, made in gold and silver with embedded old cut diamonds and diamond splinters. A similar Brooch is published in the book: BUCCELLATI TIMELESS ART pag.54
The weight of brooch is 14,2 gr., the central diamond is estimated 1.5-2 ct. plus other 3.3 ct. diamonds circa. The brooch is signed by M. Buccellati on the pin as usual for that kind of jewel.