This base is based on the tanzanite gem a very rare blue and violet gemstone found only in Simanjiro District of Manyara Region in Tanzania it is one of three December birthstones and was added to the list in 2002. It was the first gemstone to be added to the official birthstone list since 1912.
With line art:

https://i.imgur.com/MDWdjNO_d.webp?maxwidth=640&shape=thumb&fidelity=medium


with out:
https://i.imgur.com/28ovWhA_d.webp?maxwidth=640&shape=thumb&fidelity=medium