I sometimes get asked where I find jewelry for my shoots. Here's a little bit on how I do it.
First, I study the era or style in which I want to shoot. Generally, I shop Etsy for used jewelry items in the fashion that I'm looking for. I find that there are plenty of shops that source 1940's, 1950's, 1960's, etc items at reasonable prices. Occasionally, I will go to Amazon or eBay for new pieces.
I picked up the following piece for a 1940's photo shoot recently. There are many, many stores on Etsy from which to choose or even other online shops such as www.ladyandlibrarian.com. With a little bit of sleuthing, you can find great bargains for your photo session easily.