Than Đá

== Vietnamese == === Etymology === than (“coal”) +‎ đá (“rock”), calque of Chinese 石炭 (thạch thán, “coal”), from Chinese 石炭紀 / 石炭纪 (Thạch Thán kỉ). === Pronunciation === (Hà Nội) IPA(key): [tʰaːn˧˧ ʔɗaː˧˦] (Huế) IPA(key): [tʰaːŋ˧˧ ʔɗaː˨˩˦] (Saigon) IPA(key): [tʰaːŋ˧˧ ʔɗaː˦˥] Homophone: than đá === Proper noun === Than Đá (geology, dated) synonym of Các-bon (“Carboniferous”)