Why didn't the ancient copper ring change color? Let's talk about it

1. The air quality in ancient times was better than that in modern times. There is no chemical composition in the air, and the copper ring will not change color because of pollution.

2. The people who wore bronze rings in ancient times were basically upper-class people. Without work, natural rings will not wear and change color.

The ancient copper smelting method is different from the modern one. The purity of bronze is high, so the ring will not change color naturally.