| In the south of the island there are sills and dykes of felsite, quartz-porphyry, rhyolite, trachyte and pitchstone. |
| Similarly, Arran pitchstone has turned up in Ireland and Orkney, highlighting the complex exchange networks between these places. |
| I have brought from that locality a single specimen of pitchstone, perfectly resinous, bleak and shining. |
| The lavas comprise dark pitchstone, resembling that at Kirk Yetholm, and porphyritic and amygdaloidal andesites and basalts. |
| Also found was a flake of green Arran pitchstone, thought to be a waste fragment from the manufacture of a tool. |
| The lavas are curious from abounding in, or rather being in parts composed of pitchstone. |
