MineArchiveA very hard, fine-grained rock formed where heat from intrusive igneous rock baked clay-rich material; in Antrim, the Interbasaltic laterite baked by dolerite plugs, prized in the Neolithic for polished axes.
Porcellanite
Mines
| Mine | Region | Worked |
|---|---|---|
| Brockley Porcellanite Quarry | County Antrim | Neolithic, c. 3800 BC–c. 2500 BC (end of Neolithic axe production) |
| Tievebulliagh Axe Factory | County Antrim | Neolithic, c. 3800 BC (axes dated 3800-2500 BC)–c. 2500 BC (end of Neolithic axe production) |