Pebbles 6-10 TDPIR The pebbles on the beach at Trabeg on the Dingle Peninsula in Ireland exhibit the range of colours to be found in Devonian mudstones and siltstones that have been encapsulated in the nearby conglomerate strata in the cliff. The colours of pebbles always look brighter and more pronounced when they are wet. I cannot remember whether these had just been exposed by the retreating tide or were wet from the rain.