KanjiJLPT N4
Quality

substance, quality, matter, temperament

Mnemonic

To test the quality of an axe, a blacksmith grabs a second axe and clashes them together—sparks fly! The one that survives without chipping is worth the money. That's how you know true quality: it endures the test and earns its price.
Additional thoughts
Picture two axes striking each other in a shower of sparks, then a bag of money slapped on the counter for the superior one. Two axes + money = the ultimate quality check.
Quick recall
Two axes clash; only the one worth the money proves its quality.

Details

The keyword for 質 is quality. This kanji refers to the inherent nature, substance, or essential character of something. It conveys the idea of what something is fundamentally made of, both in a physical and abstract sense. It can also relate to the concept of pledging or pawning, where one offers something of substance as collateral.
On'yomi
しつ、しち、ち
Kun'yomi
たち、ただ.す、もと、わりふ