Material · lithic
Obsidian (Obsidian Cliff)
North America — Great Plains, North America — Eastern Woodlands
Obsidian Cliff obsidian comes from a lava flow in Yellowstone National Park that was quarried from Paleoindian times and supplied nearly all the obsidian in Hopewell mounds a thousand miles to the east. It is a National Historic Landmark. Its presence in Ohio is one of the great examples of prehistoric exchange.
| Kind | lithic |
|---|---|
| Regions | North America — Great Plains, North America — Eastern Woodlands |
Sources
The cliff is a rhyolite flow between Mammoth and Norris in Yellowstone National Park, Wyoming, with quarry pits along its top; all collecting is prohibited. Secondary cobbles occur in the Yellowstone and Gardner rivers.
Identification
The obsidian is black, glassy and translucent in thin sections, indistinguishable by eye from other sources; XRF and neutron activation identify its chemical signature. Ancient pieces show hydration rims.
Substitutes and fakes
Modern collecting at Obsidian Cliff is a federal crime and any point claimed as Obsidian Cliff without sourcing is unverifiable. Hopewell obsidian bifaces in particular are museum objects, and any offered privately is suspect.
Cite this article
Stratum Study. "Obsidian (Obsidian Cliff)" (Material). Stratum Study pack 2026.09, as of 2026-09-21. https://stratum.black/study/materials/obsidian-obsidian-cliff. Accessed 2026-09-21.
@misc{stratum-obsidian-obsidian-cliff,
title = {Obsidian (Obsidian Cliff)},
author = {{Stratum Study}},
howpublished = {\url{https://stratum.black/study/materials/obsidian-obsidian-cliff}},
year = {2026},
note = {Material article, Stratum Study pack 2026.09, as of 2026-09-21; sources: stratum. Accessed 2026-09-21.}
} Citations carry the pack version and the article's as-of date so they resolve to the same text later. The facts themselves belong to the sources listed below; cite those for the science.