Thanks.
I forgot to add the wood species I used, bilinga, padauk, copaiba, purpleheart and beech.
The border is 1/2" and the inner pieces are 1/4", the back is filled with epoxy.
I have a lot of different woods from an online marketplace seller (sort of a Dutch version of Craig's list) who sells 1/4" floor tiles, ideal for making pendants. For making teethers I have 1/2" boards in 4 different species. Combining them makes it look solid