What Blocks Are Corruptable?(or crimson)

[ツFURY]

So I'm looking to use stone slabs for my hellevators to contain the corruption for preparations for hardmode. And I've also created an artificial crimson biome with blocks I've brought from another world, and I want to use stone slabs to build around it as well. However I'm not sure if stone slabs are resistant to corruption/crimson. Would apprieciate some help from you guys.

[Scyntell]

If it's player made there's a very good chance it cannot be corrupted. IIRC only ice, dirt, and stone can be directly corrupted. Mud will be turned into dirt at a very slow rate in HM.

[Scyntell]

Oh, and sand.

[Rosenkreuz]

if i remember right crafted block should be resistant but really go check the wiki or something

[ツFURY]

Originally posted by Xionist:

If it's player made there's a very good chance it cannot be corrupted. IIRC only ice, dirt, and stone can be directly corrupted. Mud will be turned into dirt at a very slow rate in HM.

I've heard that corruption thorns or whatever can grow somehow on the stone slab and spread corruption, is that true?

[serker31]

Stone, sand, grass. Rest is not affected by corrpution/crimson/hallow in any way. Even pure dirt is not, if there is no grass on/in it.

[Ethril]

(TL;DR version at the bottom)
All three (corruption/crimson/hallow) will convert normal grass (which can then grow on exposed surface dirt as normal grass does), stone, sand and ice. I forget the exact range, but I believe a gap of 4 tiles will prevent it from continuing.
Corruption and Crimson can spread via thorns, but those will only grow on grass.
Corruption will also convert jungle grass (but NOT mushroom grass!), and slowly convert nearby mud into dirt (so that it can continue spreading).
Hallow will not affect the jungle at all (except during the initial "rays" upon entering hard mode? Maybe? At any rate, it's not a terrible idea to splash a bit of Hallow/Mushroom around the edges of your jungle to protect it from Corruption).
I know that Crimson USED TO not affect the jungle, but I don't know if that was changed after 1.3.

Basically just use wood, clay, snow, bricks, and/or ores(!) to contain it. (also, virtually any player-crafted block will do; that includes your choice of stone slabs. Pumpkins and Candy Cane blocks are also safe, and easy to obtain en masse if you're playing during the holidays!) Maybe dig a trench around it too just in case. These biomes can, after all, spread past a wall if it's too thin. (Again; 4 blocks of non-convertable blocks, or empty air for that matter, will suffice in most situations)

One more thing of note: Smashing a Demon/Crimson Altar has a chance of converting a single tile in a random location somewhere in the world. Even if you've got the main biomes fully quarantined, you should always remain vigilant.
(That was a bit overdramatic, really; once you get your hands on a Clentaminator, it's easy to clean up any rogue biomes. Until then, powders and sticky bombs are adequate. And if all else fails, you can stop any biome dead in its tracks with a hellevator lined with safe materials. Or make a new world. Or just live in the Hallow, as unlike its dark counterparts, it does not prevent housing.)

TL;DR: You're fine just make sure there's at least 4 tiles (of safe materials and/or empty space) to properly quarantine it

[aqmlyn]

Originally posted by ✪ Fury:

Originally posted by Xionist:

If it's player made there's a very good chance it cannot be corrupted. IIRC only ice, dirt, and stone can be directly corrupted. Mud will be turned into dirt at a very slow rate in HM.

I've heard that corruption thorns or whatever can grow somehow on the stone slab and spread corruption, is that true?

Umm...last I checked, thorns don't convert bricks, wood, etc.
But somehow they do convert hallow, not sure what's up with that. Maybe it's because I hallowed a corrupt chasm.