Gromril



Gromril (a.k.a. Meteoric Iron or Star-Metal) is a metal from the warp. As the gods of Law originated from certain eddies in the warp (Law being one of the many possibilities of Chaos), so did gromril. Gromril also falls to the Warhammer World through the Old Slann warpgates. Dwarfs have discovered it in several places where meteors have struck the World. In fact, gromril is only found in the presence of warpstone. The reverse, however, is not true. Raw gromril is a silvery metal that is incredibly rare and valuable and only dwarves know how to work it. Gromril actually has more than one state. There are three methods of refining it and each method has different effects on the metal. The first method is widely known among the dwarves and turns raw gromril into the refined gromril that is used for coins, armor, shields, and weapons. This refined gromril is sometimes called Mithril by Old Worlders. The second method is not widely known among the dwarves and its secret is jealously guarded by the dwarven Master Smiths that do know it. This second method turns raw gromril into Adamant. The third method turns raw gromril into a crystalline metal known in legend as Laihtero. ==Types of Gromril== Gromril can be created into several types of metal, depending on the techniques that can make the metal even stronger or more potent then those of other metal.

Mithril

 * Mithril is the most common form of Gromril. It is refined by smelting to remove most impurities. It is twice as durable as Steel and weighs one-fifth as much. It also accepts runes and enchantments as readily as any other metal.

Adamant
*After the item is finished, its runic properties are "set" and can never be changed or added on to in any way. Whether these items would take enchantments from human wizards during the time of refining is not known and any suggestions that they would is pure speculation. Adamant weapons, armor, and shields are as durable and weigh as little as Mithril ones.
 * Adamant is created using a refining technique which involves smelting and various other secret methods to purify it. Adamant is normally magic-inert so therefore any person wielding an adamant weapon, adamant shield, or wearing adamant armor is immune to magic. In most circumstances, they cannot use it either. There is a way to enchant adamant items so that their enchantments can be used like any other enchantments on weapons or armor made of other metals. These enchantments have historically been only of the kind that dwarven Runesmiths make and must have been placed on the item in question during the forging process.

Laihtero
*Dwarven Loremasters have speculated that Laihtero is Law in its purest form and that it will not accept magic enchantments of any kind. It is a completely translucent metal and radiates Law to those beings who are sensitive to such things. It is also said that some essence of a god of Law is necessary in the refining process to create this metal. Laihtero is undoubtedly stronger than Mithril and Adamant and probably weighs even less. As it is pure Law, it is probably drains any magic completely and has great powers against Chaos.
 * Laihtero is the rarest form of Gromril ever known. In fact only one item is known to have been forged from it; Arianka's sword, Laihtendrung. Very little is known about this material save for what a few legends have to say on the subject. It is said that only one dwarf at any one time knows the secret of the refining process to create Laihtero from raw Gromril. It is also said that this dwarf may make one item of this metal in his lifetime because it takes his entire lifetime to make it.

Source

 * Warhammer Armies: Dwarf (8th Edition)