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[Avatar] Could Toph bend adamantium?

In the episode where Zoka builds his sword, he saved a little rock of meteorite that Toph could easily manipulate, also she can bend metal. What are earthbending limits?
gpt
According to Toph, she's able to metalbend because even metal contains bits of Earth, and she's actually bending the impurities ("slag") within the metal rather than the metal itself.  The baddies in Korra used highly purified platinum, which is immune to metalbending because it is mostly free of these impurities.  Any highly purified metal should theoretically be immune.