minecraft java edition - Why can't I mine this block? - Arqade

I've hammered away at the ore block in this screenshot (which I believe is diamond) but I can't break it. I've tried other tools but none have any effect. Can anyone suggest what I'm doing wrong?

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1.13.2] Legitmine tries to mine blocks that aren't visible and also not there · Issue #432 · cabaletta/baritone · GitHub