Pricing Mithral and Adamantine

[Zhorn]

Digging through the books, these are the values I've fished up.

Storm King's Thunder
Page 60: adamantine vonindod fragment, valued at 15,000 gp at 1,000 lb. (1 lb. = 15 gp)

Tomb of Annihilation
Page 63: adamantine ingot, worth 10 gp at 1 lb (1 lb. = 10 gp)

Dungeon of the Mad Mage
Page 35: mithral ore chunks, worth 25 gp at 10 lb. each (1 lb. = 25 sp)
Page 85: stripped mithral filigree, worth 50 gp per pound (1 lb. = 50 gp)


Trying to ignore art objects and composite treasures, these four entries are the closest I could see to an official valuing on adamantine and mithral in 5e.
I'm going to assume the vonindod fragment should fall into the art object or magic item category, and adamantine's value should be treated as ToA's 1 lb. = 10 gp.

Mithral ore I'm going to assume is just very impure, and once smelted it doesn't yield anywhere near a similar weight.
Normally I would have valued the filigree as an art object, but being described in the book as stripping the metal from the wall it was decorating, and gives a value based on the metal's weight, I think this should be fairly accurate.
On the other hand, Dungeon of the Mad Mage does value 1 lb. ingots of gold as having a value of 100 gp (should be 1 lb. = 50 gp). With that mistake accounted for, perhaps mirthral's value in the module should also be considered halved to 1 lb. = 25 gp.

Questions for discussion:
- Opinions on the values of these metals? (especially considering how the metals are often used)
- Where do you think the values should sit, and how do you price adamantine and mithral in your games? (talking in gp per pound of material, not additional costs of crafting)

[firelistener]

Coins are often worth much more than the metal composing them on purpose, to prevent people from melting them down. Even assuming that some people are going to do it anyway, the issuer (government or other entity minting currency) will purposely make the face value higher so that they also effectively get a profit from those people, which is part of what's referred to as "seigniorage".

With that in mind, you're correct in thinking that 1lb of coinage should not be worth less than 1lb of the raw metal. However, this can easily be sidestepped by supposing that a coin of gp is only about 49% or less pure gold. Then you have no need to adjust the value of the metal itself because 1lb of gp doesn't yield anywhere near 1lb of pure gold, just like you suggested with mithral ore. IRL it has always been pretty common to see coins like that since the inception of banking systems.

[Misterwhisper]

I have been wondering that myself.

My character is looking for Mithral to do some crafting with.

My issue is I can imagine how big one lb of adamantine is, but not sure how much mithral I would need.

[animewatcha]

Are there more 'metal pieces' that you can fish up? I don't own any of those modules/sourcebooks, but I would imagine that how much it is worth also can depend upon the region/scarcity it is found in. You might find metal a lot easier and more plentiful than in say Storm King's Thunder with everything having to adapt to the ring of winter doom and gloom.

[Zhorn]

My issue is I can imagine how big one lb of adamantine is, but not sure how much mithral I would need.
I have not seen any mention in the books of a defined volume-to-weight ratio difference between metals in 5e.
In real world comparisons you could measure such differences for large quantities of metals (non-fantasy ones anyway), but in game terms I think it is expected for all metals to just be treated as the same in that regard.
Mirthral is described as a "light, flexible metal" in the item description for Mithral Armor (DMG p182), but being as there is no mention of any adjustment to the item's weight from the norm, light could instead mean 'light in tone/colour'.
If I were to go purely by the book; I'd rule as 'not specified, treat as the same' so 1 lb of Mithral or 1 lb. of Adamantine would occupy the same volume as 1 lb. of gold.
If I'm making a DM call for just my table; I'd go by the trope of Mithral being half the weight, so 1 lb. of Mithral occupies twice the volume of other metals (so armor/weapons made of it would also have their weights halved). But that then throws up differences in calculations for different coin types if Mithral coins became a thing... so I could just as well ignore such weight alterations for the sake of simplicity.


Coins are often worth much more than the metal composing them on purpose, to prevent people from melting them down. Even assuming that some people are going to do it anyway, the issuer (government or other entity minting currency) will purposely make the face value higher so that they also effectively get a profit from those people, which is part of what's referred to as "seigniorage".

With that in mind, you're correct in thinking that 1lb of coinage should not be worth less than 1lb of the raw metal. However, this can easily be sidestepped by supposing that a coin of gp is only about 49% or less pure gold. Then you have no need to adjust the value of the metal itself because 1lb of gp doesn't yield anywhere near 1lb of pure gold, just like you suggested with mithral ore. IRL it has always been pretty common to see coins like that since the inception of banking systems.
If you want to insert that extra layer of realism into coin value vs metal purity, the DMG (p19-20) has a whole section discussing the creation of currencies whose value within a city/region is greater than their by-metal-value elsewhere. So that is at the very least a concept that can be supported by the game system (though it does advise against adding undue complexity).
However, as the game doesn't specify any coinage being of a diluted alloy outside of electrum (special case, treating as specific beats general); I'm more inclined to say that when the books say gold, it's pure gold. Same for the other metals. Silver = pure silver, Copper = pure copper, Platinum = pure platinum. If it doesn't specify that it's an alloy, then it's not an alloy. Avoid adding complexity where it isn't specified to exist.
In the case of having a coin whose value is only half that of pure gold, then you might as well just use electrum, already being valued at 1 ep = 1/2 gp = 5 sp.

In the case of Dungeon of the Mad Mage though; I'm pretty sure the value of gold ingots is an unintended error. The PHB and DMG are consistent with each other in terms of 1lb. of gold valued at 50 gp (DMG p20, PHB p157), and 50 coins weighing 1 lb. (PHB p 143). My guess is the person writing that section was thinking 100 coins to the pound rather than 50 coins to the pound, which if you're more used to metric than imperial, would be an easy mistake to have.

Now if the value of Mithral was based of the value of those gold ingots in DotMM, it would be reasonable to scale the Mithral's per pound cost accordingly (down from 50 gp per pound to 25 gp per pound), which conveniently makes for a good allignment with the Mithral Ore's value to have a general [house] rule of ore being a 1/10th value relation to a pure metal (factors/powers of 10 are always nice and simple to work with).


Are there more 'metal pieces' that you can fish up? I don't own any of those modules/sourcebooks, but I would imagine that how much it is worth also can depend upon the region/scarcity it is found in. You might find metal a lot easier and more plentiful than in say Storm King's Thunder with everything having to adapt to the ring of winter doom and gloom.
Adjusting values based on region scarcity is all well and good for individual campaigns, but for the purposes of being consistent across all modules I think it best to just stick to a single price list set as the norm. Individual merchant encounters you can scale up or down as the plot needs, but keep your book references static.

Now as for pricing out other metals, just from the books I have in front of me:
1 lb. of Iron = 1 sp
1 lb. of Copper = 5 sp
1 lb. of Silver = 5 gp
1 lb. of Electrum = 25 gp
1 lb. of Gold = 50 gp
1 lb. of Platinum = 500 gp