The symbolism comes from the Feri tradition, of which I am a student. Depicted is the Black Heart of Innocence topped with Blue Feri Fire. There are seven howlite stones representing the seven Guardians of the seven directions and the background is black, in honor of the Star Goddess.
In addition to the howlite stones, I used broken tiles and glass. The grout is un-sanded and I finished the box off by painting it with a black acrylic.
I was quite pleased that the box ended up so popular at the raffle. Many jokes were bandied around about people wanting "my box," which made me giggle and blush.