Lightbox Gallery in Modal

I am loading a five-column gallery in a modal - it's all good other than the lightbox functionality when the images are clicked - the link brings the browser to the image itself rather than opening a lightbox to browse the gallery.
I have tried to add a lightbox initialisation in the modal html, but without success:

<script>
function() {
SEMICOLON.initialize.lightbox();
});
</script>

Can you advise?

Edit: Live URL: http://jewelnet.ltd/eq/ -> second image (rings) opens the modal in question.

Hey thanks for the advice :)

I have setup the bootstrap modal to display the gallery, but it has produced other problems :D

You can see it yourself at http://jewelnet.ltd/eq/news.php

1. The modal container does not contain the gallery.
2. The gallery is not initialised on modal load, but does appear when you resize the page.
3. Clicking a gallery thumb does produce a lightbox, but the lightbox is underneath the modal (z-index)
4. Clicking in the lightbox area for the next image in the gallery closes the modal, but leaves the lightbox.

I am thinking that galleries in modals are not the way forward!

Whilst doing this I realised that I don't need a gallery modal popover, I just need the gallery lightbox to open when the 'rings' button is clicked (see first post). Is it possible to have a gallery lightbox without showing the gallery? Is lazy loading also an option with this?

Am interested in your thoughts.
Thanks :)