Gemstone Currency

Gemstone currency is an idea I love, and would love to get finished. I’ve spent forever back and forth on the concept, and am sharing my notes to pull back the curtain a little bit, and see the energy that is involved. I’d love some help, if folks think they see an answer. I hit a wall and would love some tips.

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This project is essentially a spin off of the Economicon. Reading up on it, will save a lot of energy, but at a high level, the project’s ultimate goal is to make a fantasy economy a little more viable. In practical terms, every edition of D&D uses the gold standard. They also very quickly get to a point where you need multiple wheelbarrows of gold to pay for things. To the point that most groups either have ubiquitous bags of holding, choose to leave piles of gold in the dungeon, or hand-wave carrying capacity and treat gold as an intangible resource. All are a little immersion breaking. The “Wish Economy” outlines that wishes, and magical currency, but never really gets into why you’d care about gems. The goal of this project is to include gems in a way your players (not their characters) care about as a resource, and don’t just ask you for the gold equivalent cash value.

Designing the System

The first major challenge is finding a name for the currency. We measure coinage in gold pieces, sp, cp, or the various metric based X pieces terminology and that’s something we need to replicate with gems. Gems have a big challenge coinage does not. Coins are minted, and its easy to control their value. A silver coin is worth 10 copper. Why? because we say so, and presumably silver coins might be different sizes than copper coins or gold coins, with different images stamped, different shapes, and even different purity levels. Maybe fantasy silver coins are silver plated with tin interiors. There is no similar universal standard that can reasonably be enforced for gemstones to ensure a consistent value.

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Gemstones have inherently different values, and are naturally occurring. An adventurer can, and often does, find veins of raw amethyst while traversing the plane of earth. How do we measure that? Weight is out, because density doesn’t usually correlate with gemstone value, and neither does volume. A very small diamond is generally worth more than a very large quartz.

One of the big hurdles to overcome in finding pricing for fantasy gemstones is the incredibly subjective pricing of real world gemstones. Most tend to stick to the big 4 qualities (cut, clarity, color, carat weight) for pricing, even if done in the abstract. A gem with similar scores in the big 4 may have wildly different prices at different stores thanks to mark up. And that’s at the surface level. The mines themselves have seemingly arbitrary pricing as well. Ultimately the whole thing is a tangled mess, with countless documentaries and tell-all’s about the real world hits on people trying to break into the industry or expose the scheme. These “diamond assassins” add a complexity to our problem, but they don’t make it impossible.

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We now have some generic terms for making our own, fair trade, gemstone pricing. (Which if the world adopted, would end a lot of suffering, and make a lot of people less rich. You take that one, and I’ll write about elves and princesses). We know gems are graded on cut, clarity, color, and carats. We can set raw values for gemstones by color, per carat. A Blue Quartz has a value we can put in a table per carat with all the other gems. Something like this

GemstoneColorPrice per Carat (PPC)
DiamondBlue-White1 Unit
DiamondBlue1.2 Units
GarnetViolet.7 Units
GarnetRed.8 Units
example chart without thought or math

We also want to take into effect cut and clarity. I propose that clarity be a sliding value scale. Luckily, clarity is a value the gem selling community puts a level of strictness to. They have a chart at least. Gems can range from flawless, internally flawless, very very slightly included 1, very very slightly included 2, very slightly included 1 and 2, slightly included 1 and 2, and then to included 1 2 and 3. A little hard to follow, and probably a little more granularity than we want. I’ll simplify this, and use them to provide a cost multiplier to gems.

ClarityPPC Modifier
Slightly IncludedX1.5
offhand suggestions for modifier values

Cut is the easiest of them all. For game purposes, we simply say gems have to be cut otherwise they are considered raw. We can add a skill check to with an easy, moderate, hard, and very hard DC for whatever system you are using (EX: prof jeweler DC 10, 15, 20, 25). Failure means you don’t cut the gem and ruin it, success means the gem is cut to the clarity provided above. Once cut, introduce rules about cleaning them up, but make it much harder. Maybe +5 to the DC or so.

We now have a complicated system for assigning value to gems, and how to do something with them. We still need a name for our unit, and end of the day, the best I can come up with Carat, which is used previously and thus, bad practice because its confusing. At this stage, we don’t need to name it though, so we can use Fantasy Units (FU). I ran this by a PHD in (some unexplained fancy sort of) chemistry I know, who buys and sells raw elements and turns them into other elements for a living, and the terms I got were mole or aliquat. She then went on about how “modern alchemy mostly involves gasses nowadays”. Neither of those really fit either, so my FU is the best I have so far.

Outside of naming, we still have two big issues. 1 – People buy and sell jewelry for cash, and put it in rings and crowns and stuff. We need to account for this. 2 – how is this better than using gold?

A big challenge we have, is that we want people to care about gems, but we also have people wearing jewelry with gems. Obviously people can buy them, and most people use gold. There has to be a level they can be exchanged for gold, and there has to be a reason people can do that, and a reason people generally don’t.

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Gems can still be bought and sold. That’s a reality we have to live with, as we have chosen gems as our currency. But, in our new system, gems are used in magic. Specifically, magical rituals, and magic item creation. I recommend giving rituals and magic items a requirement, of say 10FU for the cheapest. I also recommend requiring single gems, not piles of loose ones. This means people can buy and sell small values of gems, but no one sells a large or valuable gem, because its the only way to fuel big, or lasting magic. How do you price a fountain that makes unlimited clean water? A few sp or gp a day, sure, but it remains forever. Your ROI is huge, especially for beings with lifespans like liches. A magic item smith knows he can be set for a life, in gold economy cash, if he sells to the right person. Hes not going to sell it to some rich guy for a ring. Unless the rich guy pays way more than its listed value. On the flip side, he doesn’t really have much “magic value” for the small gems. Sure those can go in a bracelet, they are of no use to a mage.

You also end up with weird stuff like amber, and pearls, which honestly, I just assigned low PPC values and called gems. Good enough. This is not like the real world, and those are not gems.

To finish this off, some numbers need to be fine tuned, and ultimately, each ritual or magic item needs a FU cost associated. I recommend 10FU per spell level required for item creation or ritual performance.


So up at the top I said its not really viable, and that it breaks my heart. I’ve got two major complaints. One with no answer, and one with some direction that makes the other complaint worse.

The first complaint. Each gemstone type is relatively interchangeable. If I’m on an adventure the DM might roll for a random one, but if I’m a mage and looking to build some magic shoes, I’m going to go to to market and buy exactly what I need. There is nothing to motivate me to get a good ruby guy, or be excited we finally found an emerald mine. I’m going to the merchant, and getting 10FU of whatever. If the DM asks what sort of gemstone, I may even reply with “I don’t really care”. The fix I came up with was to tie each gemstone to a school of magic. Rubies go to evocation, diamonds to healing, etc.

The second complaint, made worse by the solution above, and ultimately why I haven’t actually finished this, is that this is very unwieldy to use. With all the gems spelled out, we are doing a pretty elaborate lookup table, and the players inventories are turning into accounting spreadsheets. If you are good with that, this pretty much works. I found its so unwieldy, players complain, and even I, the DM and author, groan a little bit when I have to double check.

Sample final table

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