Ironstone is a sedimentary rock, either deposited directly as a ferruginous sediment or created by chemical replacement, that contains a substantial proportion of an iron compound from which iron either can be or once was smelted commercially. The iron minerals comprising ironstones can consist either of oxides, i.e. limonite, hematite, and magnetite; carbonates, i.e. siderite; silicates, i.e. chamosite; or some combination of these minerals.

Freshly cleaved ironstone is usually grey. The brown external appearance is due to oxidation of its surface. Ironstone, being a sedimentary rock is not always homogeneous, and can be found in a red and black banded form called tiger iron, sometimes used for jewelry purposes.

Ironstone as a source of iron Ironstone, although widespread, is a limited source of iron (Fe). Historically, most of British iron originated from ironstone, but it is now rarely used for this purpose because it is far too limited in quantity to be an economic source of iron ore.

In construction
The stone can also be used as a building material. Examples include the parish churches at Kirby Bellars and South Croxton in Leicestershire.

Iron Ore
Iron ores are rocks and minerals from which metallic iron can be economically extracted. The ores are usually rich in iron oxides and vary in color from dark grey, bright yellow, deep purple, to rusty red. The iron itself is usually found in the form of magnetite ,hematite , goethite , limonite.or siderite。
Ores carrying very high quantities of hematite or magnetite (greater than ~60% iron) are known as "natural ore" or "direct shipping ore", meaning they can be fed directly into iron-making blast furnaces. Most reserves of such ore have now been depleted. Iron ore is the raw material used to make pig iron, which is one of the main raw materials to make steel. 98% of the mined iron ore is used to make steel.Indeed, it has been argued that iron ore is "more integral to the global economy than any other commodity, except perhaps oil

Sangan Mine
Sangan iron ore factory and mine situated around of 18 km of northeast of Sangan city and near by Khaf Township.
Accounting for 35 percent of Iran’s iron ore deposits, Sangan iron ore mine in Khaf is one of the richest mines in the Middle East region. “The discovered iron ore deposit in the mine is estimated to be about 1,200 billion tons, some 500,000 tons of which is annually exploited” Following the direct reduction process at Mobarakeh and Isfahan steel mills, the processed product is turned into ingots part of which is shipped for export.