Edziza obsidian

It occurs in at least four geological formations of the volcanic complex and was widely used by indigenous peoples during the pre-Columbian era.

[2][3] It has been recovered from archaeological sites in Alaska, Yukon, western Alberta and along the British Columbia Coast, having been used by North American indigenous peoples to make stone tools as early as 10,000 years ago.

[2] The obsidian was especially used for thousands of years by the Tahltan people who live adjacent to the Mount Edziza volcanic complex.

[4] In Alaska, Edziza obsidian has been recovered from the 10,300-year soil layer level of the On Your Knees Cave archaeological site on Prince of Wales Island.

[6] In British Columbia, two fragments of Edziza obsidian have been recovered from the Bluejackets Creek archaeological site on Haida Gwaii and are presumably of late Holocene age.