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?

minecraft java edition - How can I make a flame arrow set a block on fire? - Arqade

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

Minecraft Is Hiding These Features In Bedrock Edition VS Java Edition

How to use a minecart with hopper in Minecraft

Fully Automatic AFK Mining Machine (Minecraft Java 1.15 - 1.16)

minecraft java edition minecraft commands - How do I create unbreakable blocks? - Arqade

How To Get Illegal 32K Items & Unobtainable Blocks In 1.18+ Survival Minecraft!

minecraft java edition - How do you fix massive holes that appear in the ground? - Arqade

What triggers the Cannot Mine path in the Mine logic block? : r/Desynced