鈹かわかわ○Meanings1nounmatte (metallurgy)Technical term in metallurgy for a mixture of sulfides produced during smelting. The kanji 鈹 is rare; usually written in kana.See also: マット銅どうの製せい錬れんでは、まずかわが生せい成せいされる。In copper smelting, matte is produced first.