Mithril

It apparently looks like silver, is extremely light, harder than steel but can be shaped as easily as copper. Its behavior resembles that of titanium, aluminum and magnesium.   Titanium is apparently a surprisingly close match. It is half the weight of steel. Its color matches. Like mithril, it is one of the strongest metals and does not corrode over time. It is also extremely rare in its easily workable metal form. Plus, it strengthens materials it is alloyed with.   Platinum is similar, but too heavy. Aluminium and magnesium are too reactive, not shiny enough and too weak. But they are actually lighter than titanium. Aluminum was also more expensive than gold at one point. Napoleon III actually owned dinnerware made out of it due to this cost.

It is lighter and stronger than the same amount of steel. Apparently it can be worked with relative ease without weakening or tarnishing. It is described as being as easily worked as copper. Titanium has an ultimate tensile strength of 63,000 psi. It is 60% as dense as aluminum but twice as strong.

Ithildin is an alloy made by the elves that eventually settled Rivendell. I'm not sure what the other materials are though. This alloy has the unique property of only reflecting moon and star light. Due to the fact that pure mithril is extremely soft and malleable, the ithildin alloy is more likely to be what all examples of mithril products are actually made out of.   Titanium can be alloyed with iron, a common material for the dwarves. We know that dwarves are known for steel and the contruction of weapons, both require iron. Therefore, it would be logical to assume that iron would be the mystery compound in ithildin.   The beta C titanium alloy has a 200,000 psi ultimate tensile strength. So this could be the upper limit for ithildin. But the aluminum based 6061 alloy relies more on titanium, copper and iron - all likely metals available to the dwarves. 6061 has a maximum tensile strength of 22,000 psi and maximum yield strength of 16,000 psi.   Okay - titanium has a 5949 °F melting point. We know that is well above the melting point of steel. We know that dragon fire does not melt dwarven steel. Then, dragon fire is able to melt Nenya - the elven ring of power made out of mithril. However, ithildin was made by the elves. Nenya was made by an elf who lived in the kingdom next to Moria and frequently got mithril from Moria for artistic purposes.   This suggests to me two important things. First, that ithildin, not pure mithril, is what was used to make Nenya. Possibly all the other mithril objects we see. Secondly, that the melting point is less than that of steel.

Caradhras is literally the only area where the metal is found. While only this one mountain in one mountain range, it appears to be quite common there. It also is located deep in the lower levels of that mountain. Hence why the balrog was released.   There were other deposits - in Numenor and the Undying Lands. But one of those was destroyed by Sauron and the other is totally cut off from Middle Earth. Thus, if any more is to be found, it has to be from Moria.

Its location in the Misty Mountains suggests that it was originally created by Morgoth. It seems unlikely that this was intentional though. If it was, it was a very poor plan by Morgoth. He utterly failed to make it accessible to his own forces. In fact, it was discovered and completely exploited by the dwarves - who waged war against him. Its complete concentration in an area far away from his base of operations made this more likely.   The result is it being an accidental byproduct of the creation of the Misty Mountains is the far more likely origin. The fact it was located exclusively in the mountain Durin's Bane moved into suggests that fire might have manipulated the local rock to create the material. The island of Numenor sounds like it is volcanic but so far I have no confirmation that it is. If it is volcanic, that would help establish that extreme heat involved in the creation of new rock formations is what predicts the locations of mithril deposits.

It is the exclusive reserve of Moria. From here, the main economic power of Moria is derived. It was digging for mithril that led to the unleashing of Durin's Bane. After this and the downfall of Númenor, there was literally no new mithril being mined.   But apparently the balrog prevented the orcs from mining more of it. Thus, even for Mordor, the balrog was the primary impediment to getting mithril.

The main use we see of it is in chain mail. Most notably the shirt used by Frodo and Bilbo. But it was also used by the Elves for art. The silver writing seen on the door of Moria in the Fellowship was made with it.

And there is so much of it that in order to get it all they mined so deep they reached to the base of the mountains and released the Balrog. So, even allowing for large price fluctuations, that is a lot of money coming in.   Culturally, it was prized by the elves for art. The mithril derived alloy of Ithildin was used to decorate the Doors of Durin, the western gate of Moria. Mithril itself was also used to forge Nenya, Galadriel's Ring of Power.   The Star of Elendil was a gem set in mithril. This was worn by royalty of Númenor in place of a crown. The gem plus its mithril made it shine brightly - enough to blind orcs in battle. Interestingly, when Isildur put on the One Ring, he became invisible along with his other clothing and weapons. But the Star of Elendil did not. It continued to shine like "a red and wrathful star". It fell to the bottom of the river when Isildur died. It thus served as a valuable clue in Saruman's quest to find the One Ring. A replica was made and used in a similar role in Gondor.   Also in Gondor, the helmets used by the Tower Guards were made with mithril. The gates to Minas Tirith were rebuilt under Gimli's orders after the war with Mithril.   J.R.R. Tolkien, Christopher Tolkien (ed.), Unfinished Tales, "The Disaster of the Gladden Fields".   The extreme cost and rarity of mithril meant that it was reserved mainly for the wealthiest of people. Hence why it was primarily reserved for royalty, important heirlooms and other similar items. We can assume that anyone with mithril - any mithril - would be at the extreme pinnacle of wealth, power and status.   Titanium is used in jewlry. It allows for 24 karat gold to have the hardness of 14 karat gold. Thus, the jewelry has the durability of the cheaper, less pure gold. Meanwhile, it retains the aestetics and status purer gold grants. It seems pretty logical that for the rich and upper middle classes that might be able to afford higher end jewelry would buy a similar gold and mithril alloy based jewelry.

There does not appear to be much industrial use for titanium in industries available with medieval technology. Which fits with the fact mithril does not have any recorded use in this department.

Titanium, which is close to mithril, is actually quite common. but not in the easily usable form. Thus it would be equally as hard to find and use with medieval technology. Even today, it is extremely difficult to refine into pure titanium. Judging by the rarity of pure titanium and its difficulty in refining the ores, it would not surprise me that there are more mithril in the Misty Mountains. Just it has not been found in any form that even the dwarves can properly exploit. The cost of refinement also explains why it is so costly. Only the most expensive products available to the average consumer have titanium in it. For example Corvettes are one of the only cars that use it - often seen as a status symbol. This is perfectly in line with what we see with mithril. The cost of mithril being 10 times that of gold in Middle Earth could be as much a function of its cost to refine as much as its rarity.

Now, I have no confirmation of this, but it was probably used much more widely. The shirt of mithril mail Bilbo owned suggests this. But as this is the only know example, it hardly establishes how widespread it was. We can assume then that when Númenor and Moria were actively mining it, similar shirts of mail were made.   Titanium is a poor conductor of heat. This means mithril armor could be prized for a race constantly battling dragons.

By the time of the War of the Ring, all new mithril items had to come from melting down existing items. Sauron naturally coveted the material. therefore, most of the existing items left in Moria were scavenged by orcs and sent to Mordor as tribute.

Moria naturally is the only source, thus the main traders of mithril. Moria would also be the center of the manufacturing of products that use it.

Due to the connections with elites and their status, I would suspect that mithril would probably be subject to regulations keeping it in the hands of the elites. For example, the mail shirts like Bilbo's would reserved for high ranking commanders, nobles, royalty and royal bodyguards. Essentially anyone who has power and would want to retain symbols of that power for their exclusive use. Thus, mithril would be quite valuable as a status symbol by law and economics. This would solidify the use of mithril based items as heirlooms.