How big is a 10,000 gp diamond, 25 gp onyx, or 1,500 gp worth of ruby dust?

[Segev]

When you picture your spellcasters using these material components, how big are the components? Bouncing off the "If you were a wizard..." thread, how big would the gems you'd have to carry around be in the modern world? How much dollar value would they represent?

25 gp can buy, according to the SRD, a silver holy symbol, a guard dog, or 12.5 days in a "good room" at an inn. Avoiding absolute top-tier luxury hotels, a "good hotel" room is still probably $200+ a night, while a trained guard dog can cost thousands of dollars, and a silver pendant crucifix comes anywhere from $55 to $250 (and those look pretty small, like necklace pendants rather than something a cleric would hold up as a holy symbol to banish the undead).

So converting dollars to gp is hard. (Heck, the old American Eagle $10 coin is something like $1200 today, if not more.)

Calculating the carats or dimensions of a gem stone based on cost is, thus, tricky.

But, let's say you're a wizard in the real world, and you need to get the gems to animate some undead. (Or to make a forcecage. Or for your cleric buddy to raise somebody from the dead.) How many dollars would you have to spend on the gems? How big would they be, or how big would the pile of gemstones and gem powder be?

[OgresAreCute]

For these kinds of things I always go via goats, as a single goat is worth 1 gp. Now, goats and diamonds might have increased in value at different paces, but details schmetails :smallwink:

[Deophaun]

In general, I don't imagine size but cut. You would have your standard gem cuts for jewelry, but then you have intricate arcane cuts that are not as visually attractive in a ring but are better at holding and focusing magic, which is what creates the price.

[ezekielraiden]

Generally for something like this, I imagine the gem in question is (approximately) fingernail-sized. The largest diamonds in our world are smaller than a typical human fist--the Cullinan Diamond, the largest gem-quality raw diamond ever found, was only 177 cm3, which is about 3/4 of a cup for fellow Americans. And that had to be cut down into smaller pieces; the single largest piece of it was the Cullinan I, also known as the Great Star of Africa, and roughly 1/6th the size of the whole thing (so only about 1 oz volume, two tablespoons). That's still a Pretty Friggin Big Diamond, and nearly priceless simply for its size. Smaller stuff is easier to value, of course, and real diamond prices are basically all over the place because every single measurable characteristic of a diamond can be used (consider: the color a diamond fluoresces under UV light is a significant factor; even though you'll never see it in daylight, a fluorescing diamond can lose up to 20% of its maximum potential value!)

So yeah. I figure a 10k gp diamond is on the order of fingernail-sized (edit: and, to be clear, maybe a quarter inch/0.5 cm thick) Which makes it very, very big compared to most gems today, while still falling far short of the golfball-sized Cullinan I.

[Fouredged Sword]

Also gem value is geometric, not linear. Single large gems are worth far far more than their karot in smaller gems.

Clarity and cut also play factors, at least in modern society.

10,000 gp may be as small as a robin's egg or as large as your fist.

But that all is based on the modern world where gems are valued based on their beauty.

I argue that 10,000 gp diamonds are not the value of the diamond, but the market price for the component required to raise someone from the bloody dead.

The fact that it is a pretty clear stone of high refraction and hardness is secondary to that sort of thing.

[Fizban]

Regarding the dog comparison- I would guess that a modern "trained guard dog" is of a larger purebred breed and trained one on one with a rarer skill nowadays, while the dnd dog is a Small mutt trained alongside the rest of the kennel with a much more common skill.

Answer to the main question: not large enough to matter. I don't want to call up exact gem sizes for precisely that reason of real-world comparison, and no matter what they're not going to be big enough to matter for encumbrance. The DMG doesn't actually rate it's gems by size, instead focusing on type and quality. The most I would take from real life would be searching for what an "average" size would be, then adjusting based on the value rolled for/assigned to the gem. Then you have gem dust, which isn't even clear on whether it has it's own value or is valued based on the gems destroyed, not even gonna bother with that one.

Amusingly, the highest possible result for a blue diamond on the DMG table is 8,000gp- the 3.0 gem table does not support valuable enough gems for the much higher 3.5 raising prices. And the answer to how hard is is to find diamonds, onyx, etc on the treasure table is "hahahaha no" due to the many types at each fractional chance.

[noob]

We can get 50 living chickens with a gold coin
Let us say a living chicken have a value of 10$
You already have a 500$ gold coin
Now if you instead go by mass of gold and say a gold coin is pure gold a gold coin then is worth not so far from 300-400$
If instead with your gold you buy weightless candles they are probably worth thousands and thousands of dollars piece and you can buy 100 of them with one gold coin.

[Nifft]

The mechanics are abstract for what seem like good reasons.

So there is no single answer, and that seems like a net positive for the game.

[hamishspence]

Amusingly, the highest possible result for a blue diamond on the DMG table is 8,000gp- the 3.0 gem table does not support valuable enough gems for the much higher 3.5 raising prices.

Don't the art object tables include "huge gemstones" worth much more?

[Nifft]

Don't the art object tables include "huge gemstones" worth much more?

Huge is a well-defined size category so that clearly puts a lower & upper bound on their dimensions.

[noob]

The mechanics are abstract for what seem like good reasons.

So there is no single answer, and that seems like a net positive for the game.

I think dnd have command economy.
Some ultimate authorities commands the costs of varied products.
Then people follows.
It does not depends on the amount of the stuff since there is plans where there is literally trees on which gemstones grows and which would make material plane gemstones lose all value if a single person did plane shift and start lugging a bunch of carts of it.
Also the gemstones have that value in absolute it is nowhere written that you can not sell them at that value if you get to own some of those trees.

Then there is a rod which can make some valuables stones which have a constant value of 1 gp piece no matter the fact that once you have that rod you can spawn 800 of them a day(assuming 8 hours of work) and that the rod is worth like only 12000 gp.

[hamishspence]

Huge is a well-defined size category so that clearly puts a lower & upper bound on their dimensions.

Now that I've looked it up - I've found where I got that idea. It was from a 4E book: Draconomicon: Chromatic Dragons, which had 50,000 gp art objects, including "enormous gemstone" as an example.

[Segev]

Yeah, the question I'm kind of dancing around is two-fold, and part of it's been answered by one of the early posts. The part that's been answered is a visual representation one: just how big are these gems? I mean, a 25 gp onyx must fit into the mouth or eye socket of most Medium corpses, but how big is it?

The other one that I didn't really hammer on is... just how much is 25 gp, or 1000 gp, or 10,000 gp, in American dollars? Of course, there's no objectively perfect answer, but it'd be interesting if there was a way to ballpark it. But values don't seem to translate straight-forwardly between D&D goods and prices and real-world modern goods and prices.

But if you were a necromancer in modern America, and wanted to animate a room full of corpses left after a gang shootout, how much money would you be expending to buy all the black onyx you're going to use? Breaking it down, how many dollars-per-zombie are we talking about, when they're all 1 HD humanoid zombies?

The mechanics are abstract for what seem like good reasons.

So there is no single answer, and that seems like a net positive for the game.
Oh, certainly, it works for the game it's designed for. It's a good abstraction, because it is easy to track and is, generally, in units the players will want it in anyway. "I go buy 20,000 gp worth of diamonds, one of them for a true res and ten for regular res."

I'm not in any way faulting D&D for this choice, just trying to get a mental concept of what this would look like in terms of "real" costs today if we really had that kind of magic.

Am I buying a big enough onyx to animate a human corpse?

[Shalist]

Regarding exchange rates:

The price/scarcity of everything (not just trade goods) is drastically and inconsistently different ('all over the place'). I agree with OP that determining a simple $ to GP exchange rate based on apples-to-apples comparisons of their relative, native spending powers is, at the very least, a bit complicated.

Even assuming you ignore all the things that are readily available today (8gp for an ink cartridge, 100g for a magnifying glass, 20g for a pack of matches, etc.) and focus on more basic goods and services, there's still the matter of different RL economies to consider -- i.e. a minimum wage of $0.03/hr in Sierra Leone vs. $18/hr in Australia.

Pricing can either be arbitrary, complicated, or both. Given those options, I prefer arbitrary .

---

Per the spirit of the OP though:

Salt has a density of 2.16 g/ml (google)
Fine salt has a density of 1.136 g/ml (https://www.aqua-calc.com/page/density-table/substance/redmond-coma-and-blank-real-blank-salt-coma-and-blank-fine-blank-salt-coma-and-blank-upc-column--blank-018788102502).
=> 'Finely dusted' salt has 0.63 0.53 the original density.

Diamond has a density of 3.53 g/ml (google)
Finely dusted diamond density = 3.53 g/ml * 0.63 0.53
=> 2.225 g/ml for 'fine diamond dust, or 201.56 ml/lb
=> 1.856 g/ml for 'fine' diamond dust, or 244.324 ml/lb

Diamond has a value of 50g/pinch (http://www.d20srd.org/srd/spells/nondetection.htm)
1 pinch is ~ 1/4 to 1/24 a teaspoon (https://en.wikipedia.org/wiki/Pinch_(cooking)) (1.232ml to 0.205ml)
=> 40.584 gold/ml to 243.506 gold/ml

=> 201.56 ml/lb *(40.584 to 243.506) gold/ml => Diamond dust is worth 8,181.67 to 49,090 gold/lb
=> 244.323 ml/lb * (40.584 to 243.506) gold/ml => 'Fine' diamond dust is worth 9,916 to 59,495 gold/lb.

Note that using regular table salt (1.217 g/ml (https://www.aqua-calc.com/page/density-table/substance/salt-coma-and-blank-table) instead of 1.136) for coarser diamond dust still gives a value of ~ 9,200 to 55,400 gold/lb.

So, on average, 35,000 gold/lb (or 32,500 gold/lb for coarser diamond dust).



edit: Superficial edits (i.e. had mostly ml, but a few cm3's)
edit2: 1.136 / 2.16, not 1.36 / 2.16 (0.53 instead of 0.63) for the 'salt' portion; values adjusted accordingly, and added a note about 'regular' diamond dust being worth only slightly less.

[Deophaun]

I think dnd have command economy.
Some ultimate authorities commands the costs of varied products.
Then people follows.
I think it's more accurate to say that the D&D economy operates off the labor theory of value: it doesn't matter what you make with your craft check, you're going to be able to sell it for half (Modifier+10) * DC silver at the end of the week.

[Segev]

Regarding exchange rates:

The price/scarcity of everything (not just trade goods) is drastically and inconsistently different ('all over the place'), such that determining a simple $ to GP exchange rate based on apples-to-apples comparisons of their relative, native spending powers, at the very least, a bit complicated.

Even assuming you ignore all the things that are readily available today (8gp for an ink cartridge, 100g for a magnifying glass, 20g for a pack of matches, etc.) and focus on more basic goods and services, there's still the matter of different RL economies to consider -- i.e. a minimum wage of $0.03/hr in Sierra Leone vs. $18/hr in Australia.

Pricing can either be arbitrary, complicated, or both. Given those options, I prefer arbitrary.

---

Per the spirit of the OP though:

Salt has a density of 2.16 g/cm3 (google)
Fine salt has a density of 1.136 g/ml (https://www.aqua-calc.com/page/density-table/substance/redmond-coma-and-blank-real-blank-salt-coma-and-blank-fine-blank-salt-coma-and-blank-upc-column--blank-018788102502)
=> 'Finely dusted' salt has 0.63 the original density.

Diamond has a density of 3.53 g/ml (google)
Finely dusted diamond density = 3.53 g/ml * 0.63
=> 2.225 g/ml for 'fine diamond dust, or 201.56 ml/lb

Diamond has a value of 50g/pinch (http://www.d20srd.org/srd/spells/nondetection.htm)
1 pinch is ~ 1/4 to 1/24 a teaspoon (https://en.wikipedia.org/wiki/Pinch_(cooking)) (1.232ml to 0.205ml)
=> 40.584 gold/ml to 243.506 gold/ml

=> 201.56 ml/lb *(40.584 to 243.51) gold/ml => Diamond dust is worth 8181.67 to 49090 gold/lb

That's a helpful analysis, thanks! For gemstone price conversions, at the least, we just now need to figure out how much diamond dust is worth in dollars.

As a "superabrasive," you can get diamond dust for about $2300/lb. But diamond dust is probably heavily deflated in value by the fact that we can manufacture it now, and "superabrasives" wouldn't fall into the shenanigans performed that keep jewel-diamond prices as high as they are. This is not a rigorous move, but I'll arbitrarily multiply by 10 to get $23,000 per lb. of "jewel-quality" diamond dust (which is nonsense, but bear with me anyway). On an order-of-magnitude scale, that translates to roughly half as many dollars as the upper-end gp estimate of diamond dust per lb.

So we might assume a gem's dollar value is half of its gp value. Making a 25 gp black onyx... $12.50?

That...seems too low. I know the variance based on differing cultural norms and availabilities makes this difficult to use, but I find it hard to reconcile 25 gp gemstones being $12.50 with the fact that that same gemstone would buy 12-13 days at a good hotel (which is going to be a minimum of about $85 * 12.5 = $1,062.50...and that's for a low-end hotel/high-end motel, which I guestimate is akin to a medieval-style "good" inn room).

That said, if we do assume the gem value is right and we're just dealing with much cheaper gems today than D&D's faux time period and place, that's a pretty cheap zombie!

$500 for a diamond to resurrect your buddy is a pretty good deal, too.

From a storytelling perspective, a necromancer in D&D is able to animate two zombies for the price of living in a comfortable room for 25 days (just under a month). Assuming this is a "reasonable" price for zombies, that translates to it being worthwhile to animate a zombie if it costs up to about $1000 each.

Going into the value IRL of raising the dead is silly; any price you name is probably "worth it" to somebody, considering that it's bringing back a loved one. Even by actuarial tables, if it costs less than a million dollars or so, most life insurance policies would be HAPPY to pay to bring you back rather than pay out the benefits, if you were not very close to when they were expecting to pay out anyway. Especially the policies employers take out on valuable employees; the payment for lost work is worth less to them than getting that work.

[Maat Mons]

Then there is a rod which can make some valuables stones which have a constant value of 1 gp piece no matter the fact that once you have that rod you can spawn 800 of them a day(assuming 8 hours of work) and that the rod is worth like only 12000 gp.

Wait! Wait! I've got it!

The rod checks the current market price for gems and adjusts the size of the stones it creates accordingly. Thus, no matter how the relative values fluctuate, the rod always creates gems of exactly the right size to be worth 1 gp (at the instant of creation).

Naturally, since everyone who's anyone has quite a few rods and employs commoners to keep them churning out stones 'round the clock, gems are constantly being devalued at a staggering rate. This means, as time goes on, the stones created by the rod get bigger and bigger.

And since True Resurrection also checks the market price at time of casting, you really don't want to buy your component too far ahead of time. Those diamonds you paid 25,000 gp for aren't going to be worth 25,000 gp for long!

[Nifft]

Wait! Wait! I've got it!

The rod checks the current market price for gems and adjusts the size of the stones it creates accordingly. Thus, no matter how the relative values fluctuate, the rod always creates gems of exactly the right size to be worth 1 gp (at the instant of creation).

Naturally, since everyone who's anyone has quite a few rods and employs commoners to keep them churning out stones 'round the clock, gems are constantly being devalued at a staggering rate. This means, as time goes on, the stones created by the rod get bigger and bigger.

And since True Resurrection also checks the market price at time of casting, you really don't want to buy your component too far ahead of time. Those diamonds you paid 25,000 gp for aren't going to be worth 25,000 gp for long!

We can call it a Rod of Dow Jones-ing, which is of course a sub-type of dowsing.

I bet those people employ crysmals (http://www.d20srd.org/srd/psionic/monsters/crysmal.htm) and other such gem-consuming critters to maintain market pricing.

[Fizban]

Don't the art object tables include "huge gemstones" worth much more?


Now that I've looked it up - I've found where I got that idea. It was from a 4E book: Draconomicon: Chromatic Dragons, which had 50,000 gp art objects, including "enormous gemstone" as an example.

Had me going there for a second. I wouldn't be surprised if Draconomicon had something like that too though.

[Bronk]

Now that I've looked it up - I've found where I got that idea. It was from a 4E book: Draconomicon: Chromatic Dragons, which had 50,000 gp art objects, including "enormous gemstone" as an example.

The Molydeus is also described as having a 'large ruby worth at least 20,000 gp' in FCI. Judging by the illustration, that sucker's at least fist sized (since it's about half a large creature's fist size).

[unseenmage]

Didn't see it mentioned but my apologies if someone beat me to it; IIRC D20 Modern has a gp to dollars conversion that I've seen described as workable.

I adore threads like these as visualizing the 'real world' equivalents of game abstractions helps me with immersion and roleplay.

[ExLibrisMortis]

I would use the following guideline (regardless of what the rules say--by-the-book pricing makes no sense anyway):
- Copper is for small tips, buying a snack at a stall (fifty cents up to perhaps two euros).
- Silver is your usual carrying-around money (five and ten euro bills, up to about fifty).
- Gold is your bigger money, the stuff we'd use banks for (hundreds and up).


A day labourer earns ten euros (1 silver) a day; that's someone who loads your truck (cart) for a cheap meal, like discount frozen pizza (perpetual stew at Ye Olde Grimy Taverne (seat not included)). By that price conversion, 10 000 gp in diamonds is about a million euros, which is a decent price for a resurrection. A little browsing suggests that--on Earth today--that might be as small as an eight-point-five-carat diamond (it also comes with free shipping), which is just over 13 mm across and weighs only 1.7 grams.

Alternatively, a couple of thousand tiny low-quality diamonds, weighing about 100-150 grams together, might make up the same value.

[Telok]

So it looks like you can get black onyx for about $8/lb (American) if you buy in bulk.

http://www.crystalrivergems.com/black-onyx-brazil-tumbled-gemstones-special-8-oz-tronbb-8/

Onyx is a semi-precious stone, essentially a pretty type of rock rather than a gem or crystal. Of course diamonds also have a cartel to control and inflate prices. Still, nothing says there isn't a gemstone cartel in D&D land. It would make sense.