iron-stone
Noun (countable/uncountable): A hard, heavy sedimentary rock that contains a significant amount of iron, typically in the form of iron oxides, and is used as a source of iron ore.
- (A type of rock used as iron ore.)
- (A specific sedimentary rock classification.)
- (Historical use as raw material.)
"Iron-stone formation": A geological layer or bed of iron-stone rock.
- The iron-stone formation in this region dates back to the Jurassic period. (A specific geological stratum.)
"Iron-stone nodule": A rounded, concretionary mass of iron-stone found in sedimentary layers.
- Collectors often search for iron-stone nodules in riverbeds. (A specific physical form of the rock.)
Ironstone (noun, alternative spelling): The same rock, often written as one word without a hyphen.
- The quarry produces high-grade ironstone for export. (Same meaning as iron-stone.)
Iron-stoneware (noun): A type of durable pottery made from clay mixed with iron-stone dust.
- Antique iron-stoneware dishes are prized for their strength. (A compound word using "iron-stone".)
Iron ore: A general term for rock from which iron can be extracted.
- The iron-stone is a specific type of iron ore. (More specific than the general term.)
Siderite: A mineral form of iron carbonate sometimes found in iron-stone.
- Some iron-stone deposits contain siderite crystals. (A related mineral component.)
"Strike iron-stone": (historical) To discover a deposit of iron-stone.
- Prospectors hoped to strike iron-stone in the hills. (To find a valuable mineral resource.)
"Hard as iron-stone": (simile) Extremely hard or unyielding.
- The frozen ground was as hard as iron-stone. (Comparing physical hardness.)