Block of the Week: Bone

The bones inside your body are mostly made of an organic substance called collagen, strengthened by calcium minerals that give it both strength and flexibility. A strong, flexible skeleton is exactly what you need for doing athletic activities - without it you'd just be a puddle of flesh on the floor.

But here's a fun fact - the fossilized dinosaur bones that you see in museums aren't actually bones at all. Not any more. To understand why, you need to know how fossils are made. When a creature dies, their body normally rots away normally. No fossil. But if a dead animal is quickly buried by sand or silt - perhaps in a landslide - then the bones are protected from rotting. The fleshy parts still disappear quite quickly, eaten by worms and other things, but the hard parts - bone, teeth, and horns - get left behind.

Then here's where the magic of fossilisation happens. Over millions of years, water in nearby rocks surrounds the hard bits, and minerals in the water slowly replaces the organic material, bit by bit. What's left, once the process is complete, is a bit of rock that's exactly the same size and shape as the original bone. Which we can then dig up and learn from. So dinosaur bones in museums are actually copies of the original bones, made of rock!

Not every animal has bones, however. Insects, crustaceans, snails and some other creatures have exoskeletons made of other hard materials instead. Some animals - like the tortoise, have both! In these cases, fossils form from those hard materials instead.

Just like in the real world, fossils are pretty rare in Minecraft. You won't find them very commonly. But next time you're exploring a desert cave, or a swampy hole, keep your eyes peeled for a flash of white in the walls. You might be uncovering new evidence of the oldest, most mysterious creatures in Minecraft.