What is the yellow metal that is referred to in call of the wild?

In "The Call of the Wild" by Jack London, the "yellow metal" refers to gold. The story is set during the Klondike Gold Rush, which drives many characters, including prospectors and adventurers, to seek fortune in the harsh wilderness of the Yukon. This pursuit of gold symbolizes both the allure and the dangers of wealth, as it significantly impacts the lives of the characters and the environment around them.