KanjiJLPT N2
Iron

Mnemonic

Your vault of gold suffers a catastrophic loss—every gleaming bar corrodes overnight into dull iron! You weep, but the blacksmith grins: iron is stronger than gold ever was. He reforges your loss into an unstoppable blade.
Additional thoughts
Picture shining gold bars rusting and darkening into iron before your eyes. The loss of something precious reveals something tougher. Gold minus its luster equals iron—less glamorous but far more powerful.
Quick recall
A loss of gold reveals nothing but iron underneath.

Details

The keyword for 鉄 is iron. This kanji refers to the metallic element iron, one of the most fundamental and widely used metals in human civilization. It encompasses both the raw material itself and its associations with strength, hardness, and durability. By extension, it can also convey a sense of firmness or unyielding resolve, as in an "iron will."
On'yomi
てつ
Kun'yomi
くろがね