noun ダウンロード 🔗共有 玉髄 A form of fine-grained quartz that is nearly transparent or has a milky translucence; it fractures conchoidally. Examples : "The artisan carefully polished the piece of chalcedony until its milky translucence caught the light beautifully. " 職人は、その乳白色の半透明さが光を美しく捉えるまで、玉髄の欠片を丁寧に磨きました。 geology mineral material substance AIとチャット語彙ゲーム読解練習