Where did this symbol for copper come from?

[maxwelljgraves]

I am only familiar with the venus mirror, where did this one come from? Who started using this, and what is the significance of this symbol as related to the alchemical properties of copper?

 

[sydward]

Many different alchemist used different variations of the common symbolism. After some light digging, I’m inclined to believe that this is a more modern symbol of copper, perhaps around the timeframe that chemistry was forming. My guess is that they wanted to move away from anything deemed “mystical.”