Terraria – ny way to get a meteorite if there’s no Corruption or Crimson in the world

With the Clentaminator present in the game, this is actually quite easy, if a bit time consuming and expensive. Dig hellevators every 120 blocks across the area you want to purify. With the Green Solution equipped, float down the each hellevator twice, first spraying to the left, then to the right. I recently did this in one of my worlds, and it worked perfectly. I'd recommend checking every so often after you're done to make sure you didn't miss anything. This will also turn any underground mushroom biome to jungle, so you may want to go back when you're done and convert it back with Dark Blue Solution.

When I did this, I left large swathes of land from the surface to the underworld converted, and even brought in Crimson from another world so I had all the biomes present. Just make sure that if you do this you put wider shafts (I left six blocks) around the corrupted/crimsoned/hallowed areas so they don't spread.

Crimson appears to be a substitute to the Corruption. The first world I created after installing the 1.2 update contained a Crimson biome, which also happened to take over a neighboring desert. Various differences with Crimson include:

• Crimstone replaces stone
• Crimsand replaces sand
• Crimtane Ore replaces Demonite Ore
• Crimson Altars replace Demon Altars
• Demon Hearts replace Shadow Orbs
• A few unique item drops
• A few unique enemies (Blood Crawler, Face Monster)
• A unique boss (Brain of Cthulhu)

Otherwise, I'm pretty sure Crimson can essentially be considered an equivalent to Corruption (it appears to spread over time in the same fashion, for example).