I find the Periodic Table of Elements fascinating, and if you do too these necklaces are for you! Each pendant is made of sturdy white on black acrylic, about 1" square, with your choice of any element you wish (you can even make one up:). Etsy only allows 70 variations in the drop down menu, so if you don't see the element you want, just choose "Custom" and leave a message letting me know which element you would like.
Each pendant comes with a ball chain of your choice, choose your length and material in the drop down menu when you order.
These would make a great gift for the science lover in your life, or your chemistry teacher!