Pentagon Jewelry by Diana Davis


clip-on and pierced stud earrings, dangly earrings, necklaces -- and more!


Math is Beautiful pentagon earrings are available at:

National Museum of Mathematics, 11 East 26th Street, New York, NY
Teichmueller dynamics, mapping class groups and applications conference, Grenoble, France, June 12-29
Joint Mathematics Meetings, Baltimore, MD, January 16-19, 2019

Interested in selling Math is Beautiful jewelry?
Contact Diana Davis at dianajdavis(at)gmail(d0t)com
Wholesale order form, showing currently available designs


Samuel Lelievre and I are studying periodic trajectories on the regular pentagon. In the course of our investigations, we created a program (in Sage, using CoCalc) that draws pictures of these trajectories. They are so beautiful! So I decided to make them into jewelry to share them with the world. I make them on a laser cutter, with plywood or bass wood; see below.

Hundreds of people are wearing Math is Beautiful pentagon billiard jewelry. Those of you that have it, I hope you are enjoying it! Please let me know if you have any feedback.

Here is an info sheet, written for a general audience, about the mathematics behind the pentagons. I have been updating it as we discover new things about them!

There are countably infinitely many periodic paths on the regular pentagon. Here are the first 500 or so.


The earrings are hypoallergenic: The stud earrings are made out of surgical steel, and the dangly earrings are sterling silver.
Here are the patterns I have been printing for stud and clip-on earrings:



I make dangly earrings that are reversible, with a different pattern on each side. Just switch ears! Below are some of the pattern combinations I have been making.

Each vertical pair above shows the two sides of a given earring style. The word below the earrings is the name I have given to that style of earring.

I am also developing a necklace pendant, but I have not finished optimizing my design yet. Early, triple-thick prototypes are shown below.


Here you can see a 24 x 6 sheet of bass wood with all three sizes (stud, dangly and pendant) pentagons, in process on the laser cutter.


Below is a video of the laser cutter engraving a trajectory. At the beginning, it seems "random," and then order emerges from chaos. The laser is drawing the lines in the same order as the path that a billiard ball would take in the pentagon, if it were shot in the direction of one of the lines on this pentagon. Video has sound (background noise of laser cutter and fan).


Diana Davis
Swarthmore College, Department of Mathematics and Statistics, 500 College Avenue, Swarthmore PA 19081
ddavis3(at)swarthmore.edu