black band ironstone meaning in Hindi

Examples

1. Competition from Scottish black band ironstone resulted in a loss of trade for the mines in 1842 / 3.
2. The Monklands coal was abundant, and when black band ironstone was discovered nearby, and the hot blast furnace system of iron smelting was developed locally, and suddenly the Monklands, Airdrie and Coatbridge, was the centre of phenomenal growth in the iron industries.