Obsidian with patches and streaks of iron oxide running through it. Reddish-brown against black produces a tone resembling mahogany timber. Not wood, but stone—carrying the visual warmth of a living material.
Formed by rapid cooling of lava, like all obsidian, with iron partially oxidising during the process. The distribution is never uniform, so no two pieces share the same pattern.
Found in Mexico, Japan, and the American Southwest. A stone that suggests something organic—unusual among minerals. Touch it, and it is colder than it looks. The warmth is only for the eyes.