Black Wood Species: African Blackwood

Idea:

A rare new wood type for savanna biomes, with the full wood set: log, planks, stairs, slabs, fence, door and so on.

Why:

• There is no black wood in the game. Dark oak is brown, and crimson and warped are purple and teal. For gothic builds, modern interiors or dark floors, you now have to use deepslate or blackstone, even when you actually want wood. African Blackwood fills that gap, and its grey tones match deepslate.
• Savannas only have acacia. A rare second tree gives the biome its own valuable resource and a reason to explore it.
• It is based on a real tree. African blackwood grows in African savannas, has near-black heartwood and is one of the densest woods in the world. It is the wood that clarinets are made of.
• It is a survival goal. Because it is rare, finding it feels like a reward, like finding a cherry grove.

Proposed unique properties:

• Rare: spawns far less often than acacia
• Fewer saplings: 2.5%, like jungle, so it stays valuable but renewable
• Slower to chop: higher hardness, because the wood is so dense
• Higher blast resistance: around stone level, tougher than normal wood
• Less flammable, but not fireproof: fireproof wood stays unique to the Nether
• Its own sound: a higher, harder knock when chopped, so you hear how dense it is