Information about Black Obsidian

Black Obsidian is a natural volcanic glass, formed from rapidly cooled lava with high silica content. It appears as jet-black, glossy, glass-like masses with a conchoidal fracture and sharp edges.

It lacks crystal structure (amorphous), often forming as rounded nodules or irregular chunks. When cut and polished, it becomes a mirror-like black surface, although under strong light, it may show faint brownish, smoky, or dark grey undertones.

Uses and History

Historically, Black Obsidian was widely used for making sharp cutting tools, weapons, and mirrors by ancient civilisations including the Aztecs, Maya, and Neolithic cultures. Today, it is popular in jewellery, ornamental carvings, metaphysical uses, and sometimes as a surgical blade due to its extremely sharp edge when fractured.

Used since prehistoric times, Black Obsidian was one of the earliest materials utilised by humans for tools and ceremonial artefacts. Its widespread use by ancient peoples across Mesoamerica, Europe, and Asia demonstrates its importance in early human technological development. Today, deposits are found in countries such as Iceland, Japan, Mexico, New Zealand, and the United States.

Mineralogy

Hazards and Warnings

Can be extremely sharp when broken—handle carefully; dust from cutting can irritate lungs.

Mineral collectors should wash their hands after handling specimens, to avoid any exposure to potential toxins.

Almost all rocks, minerals (and, frankly, almost all other substances on earth) can produce toxic dust when cutting, which can cause serious respiratory conditions including silicosis. When cutting or polishing rocks, minerals, shells, etc, all work should be done wet to minimise the dust, and a suitable respirator or extraction system should be used.

Translations

Further Reading / External Links

• https://www.mindat.org/min-28877.html