noun
great weight; pricelessness; 1000 pieces of gold
Literary or classical term. Literally '1000 kin' (a unit of weight) or '1000 pieces of gold', used figuratively for something of immense value or importance. In modern Japanese, it is mostly found in set phrases like 千金の重み or 千金に値する.
彼の一言は千金の重みがあった。
His single word carried the weight of a thousand pieces of gold.
この情報は千金に値する。
This information is worth its weight in gold.
貴重 is a common adjective meaning 'precious' or 'valuable', while 千金 is a literary noun emphasizing immense worth, often used in fixed expressions.
From Chinese 千金 (qiānjīn), literally 'a thousand gold'. The reading せんきん is the on'yomi. The kanji 鈞 in the variant 千鈞 is an ancient Chinese unit of weight, reinforcing the sense of great weight or value.