I have cross sectioned pretty much every chalk on the market and a BUNCH of cubes of Master... That looks like no Master chalk I have ran across... As cheap as it is there are still several companies in China knocking it off.. You used to be able to tell by the box it came in because they had perfected the chalk labels... AM sure now the boxes are indistringuishable as well.... I showed Corey, Shane and several pros how to spot it several years ago at one of our make it happens but they would have only gotten better...