Minecraft wiki entry for Development_versions, associated text: Can be found throughout the Nether at any altitude, though it is much more common at lower levels.
Can be refined into a netherite scrap by smelting in a furnace or blast furnace.
Same blast resistance as obsidian.
Inventory item floats on lava.
Cannot burn in lava or fire.
A diamond pickaxe or better is required to mine it.
Always spawns covered by lava or blocks on all sides.