The following articles will include spoilers for Episode 4 of The Rings of Power and J.R.R. Tolkiens' works.
The discovery of mithril in the Khazad-dum mine may seem like a victory for Durin IV and the Dwarves of Khazad-dum in the Second Age, but the mining of mithril will result in the destruction and downfall of the Dwarven kingdom.
The sheer speed with which the Dwarves mine mithril throughout the Second Age results in a rapid depleted of the ore in the mines. By the time Middle-earth reaches its Third Age, the Dwarves have to dig deep to retrieve the metal. This leads to them accidentally releasing a sleeping Balrog, a fiery demon-like creature who destroys Khazad-dum, kills Durin VI, and drives any remaining Dwarves to flee their
Durins Bane is a talisman character who inhabits Moria during his travel through Moria. Gandalf sacrifices himself so that the rest of the group may escape the Balrog, and defeats the creature before becoming Gandalf the White.
The Lord of the Rings: The Fellowship of the Ring and The Hobbit: The Battle of the Five Armies are the first movies to feature mithril. The mithril shirt is given to Bilbo by his friend Thorin Oakenshield (Richard Armitage), who later passes it on to his nephew Frodo. Frodo is saved from being fatally stabbed by a spear by the mithril chainmail shirt.
Although Tolkien did not elaborate much on the origins of mithril in the Second Age, we do know that the metal was used to forge at least one of the Rings of Power in the future. Nenya's Galadriels is the only ring we know for sure is forged from mithril, but given the lack of information on other rings made, the series may decide to have more than one ring forged from this powerful metal.
Thorin's gift to Bilbo is a significant event because it entails a love for the glittering quality mithril has, requiring the Dwarves to create elaborate gateways and etching that can only be seen in starlight or moonlight. This is why Thorin's gift to Bilbo has a symbolic value connected to his childhood as a Dwarf.
It's difficult to say no to the discovery of Disa and Durin IVs in The Rings of Power knowing what this means for their future. Because this is a prequel, and what happens to Khazad-dum is already laid out quite clearly by Tolkien, there isn't much the series can do to alter the fate of the Dwarves and their kingdom. However, it will be interesting to see how the series manages this golden age of wealth and prosperity for the Dwarven kingdom and