Without seeing your website I feel slightly disadvantaged but...
Lets talk about photography. Look around and see what you might have in your showcases that would make a good background or prop. Grab a large cardboard box, cut two sides off it (and the top) and make it white inside.
Drape some velvet type material or something in your 'light box' and place your jewelry on your prop. Light it up from left right and above then take a couple digital photos from several angles (I know if you've been doing this in your own shop you probably have a good eye for displays by now).
Pick one photo you like (maybe two or three) or else try something different and do over. I'm a trial and error photographer. Digital means we can take lots of images and discard the ones we don't like. Play around with colored lights if you wish, spot lights, you can have a lot of fun with this.
Now depending on your web software you'll feature this item on your main page. Describe it, exclaim it's beauty and features. Let the picture tell a bunch of the story! Add a price and availability. Add your other image(s) if you have them.
Now take essentially the same pieces of the images and textual content... guess where I'm going to send you. Yeah, Facebook!!!! You're going to build a post on a Facebook Page (or atleast your profile) but I want you to create a Facebook Page for your business. Share this out on your page then share the post to your profile.