Is Obsidian mafic or felsic? - Quora
Basalt is available in black, brown, light to dark grey colors whereas, Obsidian is available in black, blue, brown, green, orange, red, tan, yellow colors. Appearance of Basalt is Dull and Soft and that of Obsidian is Shiny. Properties of rock is another aspect for Basalt vs Obsidian. The hardness of Basalt is 6 and that of Obsidian is 5-5.5.