Adamantine

Adamantine was a jet-black alloy of adamant and other metals. Usually black in color, adamantine had a green sheen when viewed by candlelight or a purple-white sheen when viewed by magical light.

It was found only in veins of ore near earth nodes and areas of faerzress in the Underdark. Occasionally, small meteorites consisting of some adamantine would fall to Abeir-Toril as well.

Applications
Adamantine, when smelted, was ultra-hard but this was a costly procedure. Adamantine weapons were useful for damaging the weapons and armor of opponents. A set of adamantine armor or a shield was nearly impenetrable to normal weapons.

Adamantine was often used by drow elves of the Underdark, and their adamantine weapons were usually swords that were magically enhanced. Their magical strength and sharpness faded if brought into contact with direct sunlight.

The githzerai used their knowledge of Limbo to bring a shard of it when they traveled to the Prime Material plane. A group of anarchs then molded that essence of Limbo into large adamantine citadels that served as remote bases from which to observe enemies or to launch attacks.

Production
Naturally occurring adamantine was mostly found in meteorites and rare mineral veins.

Adamantine was extremely difficult to produce, requiring high forging temperatures and a very delicate procedure. As an alloy, it was composed of five parts adamant, two parts silver, and one part electrum. Most smiths that specialized in producing adamantine were dwarves, particularly those from the ancient kingdom of Ammarindar.

It was also possible to produce adamantine as an alloy of mithral and steel through the application of several magical procedures, although the process to do so was exceedingly complex.

Mines
Natural adamantine was mined in the following places in the Realms:
 * Greypeak Mountains