obsidianlike

Obsidianlike is an adjective used in geology and materials science to describe surfaces, rocks, or materials that resemble obsidian—the natural volcanic glass—in visual appearance or textural properties. It implies a dark, glassy look, often with a smooth, conchoidal fracture, and generally a high reflectivity similar to obsidian.

In geology, true obsidian is a natural volcanic glass formed by rapid cooling of felsic lava, producing an amorphous solid with a glassy luster. Obsidianlike materials may include actual obsidian or other volcanic glasses, and artificially produced glasses or glassy slags that mimic obsidian. The term distinguishes objects that appear obsidianlike from those that are crystalline.

Characteristics typically associated with obsidianlike materials include a dark color range (black to olive-green), a smooth, homogeneous surface, and a conchoidal fracture when broken. They may be translucent at thin edges. The term does not imply a specific chemical composition beyond a silica-rich glassy nature.

Use and context: In field descriptions, "obsidianlike" may describe rock fragments or artifacts that resemble obsidian in glaze and texture, without asserting exact formation history. In manufacturing, it can describe glass finishes and polymers designed to emulate the visual traits of obsidian.