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Yeah the pattern of his stone is similar but different. His 3rd pic is exactly how one of mine looks upclose though.

The stone in the middle of my pic actually came with a labeled box so not all...

I think it's better to round the edges instead of a 45 degree angle. You don't have to lap away all the chips but you should round the edges of the chips.

Here are some of my DBs for comparison....

It reminds a little bit of a Dalmore Blue, a sandstone ranging from coarse to fine. I don't think it is one but it might be similar.