Hi Henry, please read this attached 3 pager, from SGS, one of the world's leaing laboratories. You will see that the processing routes of different product sizes are very different and hence the grades cannot be the same.https://www.sgs.com/~/media/Global/Documents/Flyers%20and%20Leaflets/SGS-MIN-WA109-Hard-Rock-Lithium-Processing-EN-11.pdf