Qualla: Hoshigato Obsidian Mine Site

Hoshigato Obsidian Mine Site: Introduction

Mon, 16 Feb 2026 00:00:00 GMT

Three hundred kilometers is a long way to carry a stone. Yet for roughly four thousand years, beginning around 5,000 BCE, the obsidian pulled from shallow pits on the northwest slope of Mount Kirigamine traveled that distance and more, reaching settlements from the Tohoku region in the north to the Tokai region in the south. The Hoshigato obsidian mine site, perched at 1,500 meters elevation in what is now Shimosuwa, Nagano Prefecture, is one of the most significant prehistoric mining operations ever discovered in Japan -- 193 interconnected pits sprawling across 35,000 square meters of mountainside, a testament to the Jomon people's appetite for volcanic glass and their capacity for long-distance trade.

Hoshigato Obsidian Mine Site: Glass from Fire

Mon, 16 Feb 2026 00:00:00 GMT

Obsidian forms when felsic lava cools rapidly, producing a natural glass so sharp that a freshly fractured edge can be thinner than a surgical scalpel blade. The volcanic formations around the Kirigamine Highlands in central Nagano created rich deposits of this material, and the ...

Hoshigato Obsidian Mine Site: An Ancient Supply Chain

Mon, 16 Feb 2026 00:00:00 GMT

What makes Hoshigato extraordinary is not just its scale but its reach. Physicochemical analysis -- essentially fingerprinting the obsidian's chemical composition -- has confirmed that material from these mines ended up in settlements distributed across an enormous swath of Japan...

Hoshigato Obsidian Mine Site: Discovery and Silence

Mon, 16 Feb 2026 00:00:00 GMT

The site was first identified in 1920, but serious archaeological investigation did not begin until excavations between 1959 and 1961 revealed the full extent of the mining operation. A subsequent dig in 1997 added further detail to the picture. In 2015, the Japanese government d...

Hoshigato Obsidian Mine Site: The Highland Obsidian Belt

Mon, 16 Feb 2026 00:00:00 GMT

Hoshigato does not stand alone. The Kirigamine Highlands and the broader Yatsugatake region form one of Japan's most important obsidian source areas, with multiple extraction sites scattered across the volcanic landscape. The area has been designated part of a Japan Heritage stor...