Probably resin but maybe clay detailed Aztec calendar

Hi, I am pretty sure this is small Aztec/Mayan calendar wall plaque is made of resin but at first I thought it was clay. The detail is very good and I am wondering what the process for impressing the image would be? Also there are gold flakes that seem to turn purple when rubbed or scratched and I have no idea what that is about. It measures around 4.75" in diameter. Any help or ideas will be appreciated.

 

Looks like Resin to me. No idea what the added flakes are?

 

Thanks, I did find several similar resin examples with gold or bronze finish so this may have originally had something like that, but these really look like individual flakes.

 

Think yours is meant to mimic jade, also used by these cultures.