Dress for a prom or weddings or for something spec

Baby blue long flower silk like material at bottom and sleeves. Then has beautifully designed bead work around chest front and back. Also around the end of sleeves which I tried to show in the pictures. There are also big rhinestones on the top between the beading. My grandmother wore this once to her 75th birthday party. It was then dry cleaned and left alone. She is now 104 years old so the dress must be vintage. That was 29 years ago but this dress is so beautifull I know it is still relevant