What is the difference between serpentine and obsidian? Do they belong to the same category?

Personal understanding: serpentine jade is a variety of Xiuyu jade. Obsidian is a kind of volcanic rocks, and the two textures are obviously different. Obsidian is black or black with smooth eyes. If there is a broken fracture, it is a smooth surface with a glass fracture, while serpentine jade green or dark green also has black, but there is no smooth eye. If the fracture surface of the fracture is a stone micro-particle section, it is almost the same. And it's not the same kind of gem.