This is an antler hammer dog chew. My daughter bought it for me for Fathers Day from a ‘Pets are Us’ shop in Stockport, apparently dogs love chewing them. An archaeologist that was based in York, Ben Elliot, did an experimental project making antler barbed points. When he soaked the antler to make it easier to work, it ‘bled’ into the water. Perhaps this is the canine attraction. This one cost about £7.00 and it works really well for thinning the beer bottle bottoms for arrowheads. I have a similar larger one (about £12.00), from the same source, that works well on larger handaxe size pieces.