Graystane has been claimed as an erratic and also as having come from a nearby quarry, but Orkney is littered with sites labelled quarry so that is not a useful argument. It looks the genuine article to me and others. The Burns of Myres 'flaked' stone is my contender for the Giant's Thumb, when I put my thumb in front of where the concavity is the edge of my palm fell naturally at the other edge where the definite flaking is. I could bury the web with sites that could be standing stones but don't. And indeed there are accepted standing stones that strike me as chance claims to fame - though mostly of lesser size I have seen plenty of stones in the same placing regarding quarries as the Deepdale Stones of record. Another function of TMA is to put up sites for others to visit and clarify, whether recorded officially or no, otherwise we become simply an adjunct of the National Monument Records (which no longer add newspaper dig reports of new sites and so miss them).