ferroakermanite

例句：

1. 1. This ironstone is very hard and can be used for making tools.
   这块铁石非常坚硬，可以用来制作工具。
2. 2. The ironstone mine is located in the mountains.
   铁矿矿位于山区。
3. 3. The ironstone was found in the area where the ancient city was located.
   这种铁石是在古代城市所在地区发现的。