Here's a brief topic you probably already know about, but just didn't know it had a name.
Have you ever signed up to a website and had a confirmation email sent to you? Have you ever forgotten your password and requested the website send you an email confirmation to prove your identity? Have you ever received a purchase confirmation email from a website after placing an online order?
All those emails are referred to as "Transactional Emails." In fact any email that someone requests from a website in some form or another falls into this transactional category. It's important to understand the value of these emails because in 2003 the CAN-SPAM Act specifically defined what they were and that you (the website owner) do not need permission to send this type of email.
Although the internet industry refers to these as "transactions" I feel you should view these as another form of "engagement" between you and your customers. Every time a customer requests information you should not only provide it, but also give them something extra within that email.
Here are some actual implementations that I've set up for customers over the years. You would have to ask your website programmer to set these up because this thinking is pretty far out of the box.
When a customer signs up on your website...
Send them a thank you email with all your contact information. Invite them to connect with your jewelry store on Facebook, Twitter, YouTube, Google+, and any other social site. As a special thank you, you could also send them a limited time promotion if they visit your store.
When a customer requests their password...
Send them the password reset email. The person who has forgotten their password probably hasn't been to your site in a while which makes this the perfect opportunity to tell them about all the new things happening in the store that they might have missed. Along with the password reset you could tell them about your recent event or new inventory, and give them a special offer if they decide to come into your store an make a purchase of that new inventory.
When a customer fills out your contact form...
The average jewelry website owner should receive at least one email through their contact form per week. If this is not true for you then find out why your website is not performing. Send a general thank you automatically as soon as they click the Submit button. That email should also include any upcoming special events, announcements, or hints of what they should look for in the future on your social site or website.
In that thank you email you should also tell them about all the other ways you are always available for them, as in, they can call you, send an email through Facebook, use the @mention feature on Twitter, share a private message with you through Google+.
Those are just some basic ideas on how you can use an automated email to grow more business for your jewelry store. Ideally you need to have your website programmed to allow for constant changing of these messages. If this is impossible in your website then you should consider a website upgrade.
One final thought: Don't confuse transactional emails with email auto-responders. An auto-responder is an automatic email reply to someone when they send you an email, like when you set up your vacation away message on your own email account. Transactional emails are triggered because of someone's interaction with your website through their web browser; the byproduct is an email.