ギヤマン石せきMeanings1noundiamondarchaicArchaic term for diamond, derived from Portuguese 'diamante'. Used historically; modern Japanese uses ダイヤモンド or ダイヤ.江え戸ど時じ代だいには、ギヤマン石せきは珍めずらしい舶はく来らい品ひんだった。In the Edo period, diamonds were rare imported goods.
