11,500 Years of Human Tool Use Preserved at Obsidian Cliff

X-ray technology has allowed researchers to identify the unique geochemical fingerprint of obsidian from Yellowstone's Obsidian Cliff, which has been used by Indigenous people for over 11,500 years to make deadly knives, razor-sharp spear points, darts, and arrowheads. The obsidian columns have helped reveal the travels and migration of people thousands of years ago, and the technology has become easier to use, more portable, and far less expensive. Obsidian is among the most prized tool stones in the world, and this particular deposit is exceptional because of its continual use by Indigenous people since the last ice age.