At the time of discovery it was considered that a quartz revetment would have been unstable . Quartz is often found in association with monuments e.g. kerb cairns sometimes as a pavement an Irish example is Carnagat in Tyrone .There are countless other examples from Argyll Perthshire , at Newgrange there was also a pile of deposited quartz to the right of the entrance this would not have been part of a wall due to it's shape plus there was a similar feature at Loughcrew .