Material · lithic
Banded slate
North America — Eastern Woodlands
Banded slate is the grey-green to black slate with light and dark banding carried by glaciers from the Canadian Shield into Ohio, Indiana and Michigan, and used from the Archaic through the Woodland period for bannerstones, birdstones, gorgets and pendants. It is the classic material of the Ohio Valley slate industry. Fine banding raises value.
| Kind | lithic |
|---|---|
| Regions | North America — Eastern Woodlands |
Sources
The parent rock is Precambrian Huronian slate of Ontario, carried south as glacial cobbles across the Great Lakes states; artisans selected cobbles from till and streams. There are no quarries.
Identification
The slate is fine-grained, dark grey-green, green or black with parallel banding in lighter and darker shades, sometimes with red or purple; it takes a smooth, low polish and shows drill rings in perforations. Weathering produces a lighter, slightly chalky surface.
Substitutes and fakes
Modern slate objects are cut from quarried roofing slate or fresh cobbles with power tools, showing straight drill holes and uniform polish; genuine pieces have tapered reed-drilled holes with rings and hand polish. Banded slate fakes have been made since the 1890s.
Cite this article
Stratum Study. "Banded slate" (Material). Stratum Study pack 2026.09, as of 2026-09-21. https://stratum.black/study/materials/banded-slate. Accessed 2026-09-21.
@misc{stratum-banded-slate,
title = {Banded slate},
author = {{Stratum Study}},
howpublished = {\url{https://stratum.black/study/materials/banded-slate}},
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.