D&D 5E Calculating a fist-sized diamond

[aco175]

I always let PCs pool their diamonds to get the value they need. It is hard to find a 5,000gp diamond, but 20 diamonds that equal that amount is fine. It is all getting turned to powder anyways.

The whole argument is meh to start with. I could get a tiny gem worth 5.000 if it is perfect in quality and such, or a fist-sized one that is poor quality, but may be worth 5,000. Or- gem cutters collect their powder and sell it. Or- PCs go to a store and the dealer tells them it is 5,000 and could be worth anything, but the PCs believe it is the right one and it works?

 

[EzekielRaiden]

A fist is roughly a cup in volume, or about 237 cubic centimeters. Diamond has a density of 3.51 g/cm^3, so a fist-sized diamond would have a mass of about 237*3.51 = 830 g. One carat is 0.2 g, so we can estimate that a diamond at fist size after cutting would be approximately 4150 ct. That's about 30% bigger than the raw Cullinan Diamond was, and that diamond got cut up into several smaller diamonds; the largest single diamond cut from it, the Great Star of Africa which adorns the top of the Royal Sceptre of the United Kingdom (part of the Crown Jewels), is a mere 530 ct, about 1/8th the size of our hypothetical fist-sized diamond. The Great Star of Africa is estimated to have a worth of over $400,000,000, though we only have estimates because it is unlikely to ever go up for sale or auction.

A cut diamond about eight times larger than the single largest cut diamond known on Earth? We have no real way to judge its value. On Earth, it would be effectively priceless--or, rather, worth literally whatever the person who wanted it most was willing to pay for it, making its currency value entirely arbitrary.

In the context of 5e? A fist-sized diamond is worth whatever the books say it is, because we have no idea how common or rare large gemstones are. Realistically speaking, gemstones appear to be fantastically more common in the Forgotten Realms than they are on Earth, because unlike Earth, you have a process that completely consumes gemstone-quality gems. The vast majority of gemstone-quality gems on Earth either get locked up in fancy places (like the aforementioned Crown Jewels of the UK), or become adornments on the bodies of various rich people across the years, depending on who can afford to buy/lease them.

Unless there's some sort of extra source of gemstones, FR and various other settings should have rapidly run out of them centuries ago, given the sheer number of highly active spellcasters consuming them as spell components or in crafting magic items.

Edit:
I'm genuinely curious. Where did you get the idea that the diamond for true resurrection has to be "fist-sized"?

 

[aco175]

Remember the movie, The Core with the giant diamonds on the trip to the center of the Earth. Dwarves or elementals or something could go and get them.

 

[J.Quondam]

Diamonds are literal candy for xorns*, so I imagine a few reasonably stable links to the Plane of Earth would keep a Prime Material mine flush with the things?

* Complication: Gold is also literal candy for xorns. No wonder the economic metrics in D&D are all botched!

 

[Ancalagon]

As going by carats, each carat of a diamond weighs 0.000440925 lbs. (0.20000021574225 grams)
And if we were to say that a diamond could weigh 10 lbs, then that would make it a 22679.6 carat diamond. (4535.92 grams)
The current largest diamond in the real world is the Cullinan Diamond which is 3,106.75 carats or 1.3698422661 pounds (621.35000000647 grams)
The Cullinan Diamond is worth $400 million dollars.

To humor the idea, let us briefly consider D&D people weighing a fist-sized diamond in its weight in gold.
The hand of an average adult human weighs approximately 1.03 lbs, rounded down to 1 lb.
Gold in turn has a weight of 1lb per 50gp.
That in turn would mean the diamond is 2267.96 carats and weighs 1 lb. (453.592 grams).
I think we can all agree that such a comparison means that the average person is getting scammed by 4550 gold pieces when they try to resurrect their dead friend.
If we wanted to stick to the idea gold and its weight and that somehow equating to 5000gp diamond, you would need to bring over 100 lbs worth in gold. (45359.2 grams)

For fun, I also have this old Dragon Magazine article (#8), since we want to chat about how 5e caputres that OSR feel.
Its stated that a 1 carat diamond is worth 200g on average. So simply put a 5000gp diamond is a 25 carat diamond.
However, a 25 carat diamond only weighs 0.0110231 lbs or 5 grams.
Nowhere near what a fist-sized diamond would be in size.
We already calculated it would be 2267.96 carats to be 1 lb so its about the same weight as a human hand.
Which 2267.96 carats aka 1lb worth in diamond (1 carat per 200gp) is worth 453,592 gold pieces.
If we wanted to use the Cullian Diamond instead which is even more approximate to a fist-sized diamond that would be 3,106.75 carats which is 621,350 gold pieces.

So a fist-sized diamond is worth either 50gp (weight value) or its worth 453,592gp (market value).

the value of diamonds is not weight based, unlike gold.

If I have 40 little gold lumps of 1 g each, they are of the same value of a small gold bar of 40 grams.

However, a 40 carat diamond is worth way more than 40 diamonds of 1 carat each...

edit: I totally agree that D&D gems are more plentiful and bigger than in the real world.

 

[Lakesidefantasy]

Could you please tell me how much a diamond the size of a baby's fist would be? I very much would like to know.

 

[Umbran]

I think we can all agree that such a comparison means that the average person is getting scammed by 4550 gold pieces when they try to resurrect their dead friend.

I reject the comparison as highly flawed, as it has little to do with how we assign value to gemstones. Diamond value/price is not determined merely by weight. The value of diamonds is assigned based on many qualities - color, clarity, included flaws, cut, as well as the size.

But, you can have a large, low-quality diamond that is cheaper than a smaller, high-quality stone. When you have sto stoens of the same quality, value goes up with size, but it isn't linear. Larger stones are significantly more rare so their value is not simply a multiple of their weight.

 

[TaranTheWanderer]

I always let PCs pool their diamonds to get the value they need. It is hard to find a 5,000gp diamond, but 20 diamonds that equal that amount is fine. It is all getting turned to powder anyways.

The whole argument is meh to start with. I could get a tiny gem worth 5.000 if it is perfect in quality and such, or a fist-sized one that is poor quality, but may be worth 5,000. Or- gem cutters collect their powder and sell it. Or- PCs go to a store and the dealer tells them it is 5,000 and could be worth anything, but the PCs believe it is the right one and it works?

That’s what the spell fabricate is for. Making big gems into little gems or vice versa.

my 10th level wizard has gemsmithing and fabricate. It makes getting material components easier and, sometimes, cheaper.

 

[CleverNickName]

Some more food for thought: when it comes to gems (and other fine things), bigger isn't always better.

Depending on the clarity and color of the diamond (and whether or not those are consistent throughout the crystal), it can sometimes be more valuable if one single, large gem is cut into several, even hundreds, of other gems to be sold individually.

Say there are a half-dozen occlusions in that large crystal. If those occlusions are left in the large diamond, they would reduce its clarity (and therefore, its value). But if the gemcutter cuts the large crystal into smaller ones, and excises out those occlusions, you would have a few dozen flawless diamonds of higher value.

And suppose those occlusions were star-shaped. Removing them, and then cutting and shaping the diamond around them to create star diamonds, would create exceptionally rare and valuable gems.

TL;DR: a diamond the size of your fist isn't always more valuable than a fistful of diamonds.

 

[Dausuul]

Raising the dead requires a diamond worth at least 500GP.

So increased demand for diamonds for resurrection use will never empty out the market, it just means that as prices rise increasingly lower-quality diamonds will qualify as "worth at least 500GP"

I never know if people are saying this to be funny, or if they actually envision a fantasy world in which every spell includes a mystical commodities trader who looks up the market value of gemstones at time of casting. Does it take local market factors into account? If you're in a village where nobody can afford to pay more than a few silver pieces for stuff, do your material components stop working?

I always assume that component prices are based on the assumption of a stable market: There is a certain quality of diamond that is "raise-dead-worthy," and in the D&D world, the market price of such diamonds has settled at 500 gp. There may have been a time in the past when it was only 50 gp; then clerics discovered the raise dead spell, and most of the good diamonds got used up, and the price skyrocketed. All this happened many many years before the "present day." Over the years, the supply of fresh diamonds and the demand for spell components have come into balance at a 500-gp price point.