Bronze inscriptions show 金 as a roof (△) above 土 (earth) with two dots between — gleaming metal nuggets buried in the soil. The character froze the act of mining metal into a permanent picture. From this single image grew the meanings: metal, gold (金 alone often means "gold"), money, and Friday. Identical across 繁體 / 新字体 / 简体.

金 is one of the high-priority radicals. When 金 sits on the left of a compound, it morphs into 钅 in simplified Chinese (or stays as 金 in traditional/Japanese), and the meaning involves metal: 鉄 / 鉄 / 铁 (iron), 銀 / 银 (silver), 銅 / 铜 (copper), 鋼 / 钢 (steel), 鉛 / 铅 (lead), 鍵 / 键 (key). The Five Phases system places 金 alongside 木 火 水 土 — and Friday is "metal day" (Venus, the metal planet) in the East Asian planetary week.

Korean cultural note worth knowing: as a Korean surname, 金 reads "Kim" (김), making it the most common Korean family name (around 21% of the population). The same character on a Chinese person reads "Jīn", and on a Japanese person typically "Kane" or "Kin". Same character, three pronunciations across the CJK region depending on the bearer's nationality.

Mandarin: jīn, level 1st tone. 金 (jīn, gold), 黄金 (huángjīn, gold), 现金 (xiànjīn, cash), 奖金 (jiǎngjīn, prize money), 美金 (Měijīn, US dollar — colloquial), 五金 (wǔjīn, hardware — "the five metals").

Japanese: TWO on-readings. キン (kin) is dominant — 金曜日 (kin'yōbi, Friday), 黄金 (ōgon, gold), 税金 (zeikin, tax), 賞金 (shōkin, prize money). コン (kon) appears in older Buddhist compounds — 金堂 (kondō, main temple hall), 金色 (kon'jiki, golden color — vs. kin'iro). Kun-reading かね (kane) is the everyday word for "money" — お金 (okane, money — polite) is among the most-spoken Japanese words. Also 金持ち (kanemochi, rich person — "money-holder").

Memory aid: a roof over earth with two metal nuggets — a mine.