For the studs, I glued Lego studs to 6mm earring posts. I ever-so-slightly overfilled the back of the stud with E-6000 and then pressed the earring post onto it, letting a bit of the glue squish out and form around the post. If you make these yourself, remember that it is very, very important to let the E-6000 cure for at least 24 hours. That means don't touch them AT ALL for a full day. If you have the patience, E-6000 will form a really strong bond.
I loved these studs so much that I made myself two pairs in orange and white. Such a cute, subtle way to get my geek on!
For the dangles, I used a 1x4 bump Lego plate and again used E-6000 to glue a cord tip into the back of the Lego (by the way, I have no idea if that cord tip I linked to is the same size as the one I used-it was in my stash). After 24 hours, I attached a hook earring wire to it.
The fun thing about these is that they are totally buildable. You can attach different colored studs to the dangle earrings to match an outfit, or add more bricks to make an original design.
I have one more Lego jewelry project to show you. Come back tomorrow for a tutorial for a Lego bracelet that your child can make (mostly) by himself!