The Bug:

Ores have lower blast resistances than stone, despite taking longer to mine or even requiring higher tools.

Steps to Reproduce:

• Summon a large block of stone and diamond ores.

• /fill ~1 ~ ~1 ~9 ~5 ~9 minecraft:diamond_ore
  /fill ~-1 ~ ~-1 ~-9 ~5 ~-9 minecraft:stone
  

• Place some TNT on top and in the center of the two big blocks of stone and diamond ores. See setup.png
• Ignite both blocks of TNT.
  → Notice how more of the diamond ores are destroyed compared to the stone, therefore indicating that ores have lower blast resistances than stone, despite taking longer to mine or even requiring higher tools.

Expected Behavior:

The expected behavior would be that ores would have higher or equal blast resistances compared to stone, as they take longer to mine.

Original Description

When mining an ore block, it becomes obvious that they take noticably longer to mine with any pickaxe than normal stone would. In addition, several ores require high-tier pickaxes to be properly mined at all.

This increased hardness, however, is paradoxically not reflected when it comes to explosions. In the image examples, TNT is blown up on cubes of stone, coal ore and diamond ore, and contrary to what would be expected from mining them directly, much larger craters were left in the ores than were left in raw stone. It would be expected that ores would have higher blast resistances than stone, resulting in smaller craters, to reflect their increased mining toughness.

I'm aware this has been the case in game for over a decade, but it still seems off, and contradicts more modern changes such as MC-94013.