Quarrying for slate started on Belnahua in the late 19th century, much later than on the other "Slate Islands" of Easdale, Luing, Seil and Ellanbeich (which was joined to Seil by quarry spoil). Belnahua was the only island not owned by the Marquisies of Breadalbane, but the methods and pattern of quarrying was much the same. The island is returning to nature with thick grass and wildflowers slowly reclaiming the rusting remnants of machinery and the houses.
Worked slate lies around the preiphery of the island and on the beach I found this piece. It looks to have been worked to make a weight, maybe for a net or a piece of equipment.
Slate from all the islands is referred to as "Easdale Slate". It can be found all over the UK and around the world; the Breadalbanes held land in North America and the West Indies - many public buildings in eastern Canada are roofed with Easdale slate. It can be easily distinguished from slate qurried elsewhere (the quarries at Ballachulish, in North Wales. the Lake District etc) as it has a distinctive ripple on the surface and is speckled. Closer inspection of the speckles reveals...
Iron pyrites (fools gold). The deposits can be as much as 15mm across and make the slate glisten attractively in sunlight.
Other rock types occur on all the islands, principally Hornblende Schist and intrusions of hard Whinstone. This was a nuisance to the quarriers but was utilised for building the houses. Both types are much more readily colonised by lichens than slate.
Down on the shore, the rusy iron stain from pyrites on this slate was nicely mirrored by a crab shell
The slate breaks down to a fine black sand, making a nice contrast with the iron pyrites and with this piece of fish backbone.
Belnahua is a fascinating place and I could have happily spent much longer there. The small tidal race off the south end showed that the ebb tide was increasing out of the Firth of Lorn though - it was time to go before the paddle back to Ellanabeich became a slog. It was slower going on the return against both tide and a breeze, and I took a slightly wider line to avoid being pulled into the mouth of Cuan Sound with its strong tides.
It was pleasant however in bright sunshine with super views and time to reflect on the unique atmosphere of Belnahua. I must go back and stay overnight on the island to explore more fully.