you should have explained that thiên thạch is a Sino-Vietnamese word from 天石. 天 means sky, heaven and 石 means stone. thus thiên thạch literally means stone from the sky and is translated as meteorite.
when people will come across noun phrases containing thiên or thạch, they might not know the exact translation but they will be able to guess the meaning as it has to do with sky or stone, or at least has an origin that comes from these words.
- thiên hạ = 天 sky + 下 below = world
- thiên đường = 天 heaven + 堂 house/building = paradise
thiên tài = 天 sky + 才 talent = genius
bảo thạch = 寶 precious + 石 stone = gemstone
- cẩm thạch = 錦 bright/beautiful + 石 stone = marble
- hoá thạch = 化 to change + 石 stone = fossil