What does obsidian mean?

1, shining; Bright: "Do it at sunrise";

2. The sun, the moon and the stars are collectively called "Obsidian", and the seven-star stones of the sun, the moon, fire, water, wood, gold and earth are collectively called "Seven Obsidian". In the past, they used to call seven days a week, such as "Sun Obsidian Day" is Sunday, "Moon Obsidian Day" is Monday, and so on. This title is still used in Japan and Korea.