what is the connection between lodestone, ironstone and magnetism?

Answer 1

To answer this, and your other earlier question:

Lodestone is made of the mineral magnetitre, an oxide of iron, and having the property that it will become magnetic itself when placed in a magnetic field (caused by the crystals in the magnetite aligning themselves with the magnetic field).

Ironstone is a term for a rock rich in iron; not necessarily magnetite, but most commonly limonite, which is a hydroxide of iron, and does not exhibit the same magnetic properties. Similarly, hematite, the other main oxide ore of iron, is attracted to a magnet, but will not become magnetic itself, to the degree that magnetite does.

Answer 2

Ancient Chinese mariners used a natural iron ore piece which had a property of showing north - south direction when suspended freely. While travelling in the sea, the utilised the directive property of this material (iron ore called MAGNETITE) In other words this stone was LEADING them. & these stone were called LODE STONE. It is the natural magnet.
Pure iron is not available in nature. It will be always in the form of ores. It will be attracted by a magnet. but doesn't show any directive property which is the proper sign of magnetism.
Artificial magnets are made with specially designed alloys. These magnets will have all the oroperties as that of a natural magnet. One of the best such alloys is ALNICO which is an alloy of Aluminium, Nickel and Cobalt.