The BGS viewer showed a dyke below the camping pods at Eigg harbour. It is from the North Britain Palaeogene Dyke Suite - Basalt. I can't seem to find out much about it.
However, this rock on the side of the ridge of rock looks to have been baked. It is now very flaky. I'd say contact metamorphism.And here are views of the ridge of rock I think is going to be the dyke.