Gemstones
Gemstones are the pretty colorful stones that are fantastic to grab a handful and roll them around... or was that dice?
These shiny baubles are a common and convenient form of loot as you can compress 50 gp into a tiny gem that fits into a ring. But not every gem is equal, not every diamond is a flawless 10 carat stone found only in the rarest of loot tables, sometimes it's tiny and cruddy.
Weight and Quality
A gem's value is determined partially by its weight. The weight of gems are measured in carats or ct. for short. We do this, because if we measured them in pounds like the rest of weights in Dungeons & Dragons, then the smallest (1 lb.) diamond would be the size of a softball and be worth 1,100,000 gp.
Incidentally, this means that although the weight of a gem is important, it is also negligible.
In addition to the how rare the stone itself is and large it is, the quality of the stone matters too. There are five gemstone qualities Chipped, Flawed, Regular, Flawless, and Perfect.
Below is a table showing the value of a 1 ct. gemstone of a certain rarity and quality. The value of a particular gemstone equals the value of a gem of its quality and rarity times its weight in carats (ct.).
Gem Value per Carat
| Gem Rarity | Chipped | Flawed | Regular | Flawless | Perfect |
|---|---|---|---|---|---|
| Abundant | 1 cp | 2 cp | 5 cp | 1 sp | 5 sp |
| Common | 2 cp | 5 cp | 1 sp | 5 sp | 5 gp |
| Uncommon | 5 cp | 1 sp | 5 sp | 1 gp | 10 gp |
| Rare | 1 sp | 5 sp | 1 gp | 5 gp | 50 gp |
| Very Rare | 5 sp | 1 gp | 5 gp | 10 gp | 100 gp |
| Scarce | 1 gp | 5 gp | 10 gp | 50 gp | 500 gp |
Rolling for Gemstones
When rolling on the Treasure Hoard tables on pages 137 - 139 of the Dungeon Master's Guide you can customize your gem loot further. You may use as much or as little of these rules as you like, if you only want random weights and not quality, treat every gem as Flawless, if you only want random qualities, treat every gem as weighing 10 carats. If you don't want either, I can't help you.
The table will turn up things such as 50 gp gems or 1,000 gp gems, these have been given different names here to reduce confusion later, but the table below exists to quickly correlate the gem types between this and the DMG.
| This Guide | Dungeon Master's Guide |
|---|---|
| Abundant | 10 gp |
| Common | 50 gp |
| Uncommon | 100 gp |
| Rare | 500 gp |
| Very Rare | 1,000 gp |
| Scarce | 5,000 gp |
Random Qualities
| d100 | Quality |
|---|---|
| 1-20 | Chipped |
| 21 - 55 | Flawed |
| 56 - 90 | Regular |
| 90 - 99 | Flawless |
| 00 | Perfect |
Random Weights
| d100 | Weight |
|---|---|
| 1 | 1d4 ct. |
| 2 - 10 | 2d4 ct. |
| 11 - 40 | 3d4 ct |
| 41 - 60 | 3d6 ct. |
| 60 - 90 | 3d8 ct. |
| 91 - 99 | 3d10 ct. |
| 00 | 1d100 ct. |
Gem Cutting
Not all gems are perfect. As such, many seek to cut gems into a better shape or to remove flaws and imperfections, to improve its value.
To cut gems, you require jeweler's tools, proficiency in those tools, and gems to cut. But cutting gems isn't easy, and failure comes at material cost.
To attempt to cut a gem into a better quality, you must make a Dexterity (jeweler's Supplies) check against the DC of the quality of the gem. Cutting a gem takes an hour.
On a success, you cut the gem in a way that minimises the imperfections, while keeping it usable. Increasing its quality by one step, to a maximum quality of Perfect. Beating the DC by 5 or more lets you reroll on the cutting result table an additional number of times for every 5 you exceed the DC.
Failing the check by less than 5 does not reduce the quality of the gem. Failing by more than 5 reduces the quality of the gem by one step for every 5 you fail to meet the DC by, reducing the quality less than Chipped turns the gem into dust.
Regardless of either success or failure, the size of the gem is affected. If you cut the gem into multiple gems, you round the weight of the resulting gems down to a whole number. When you reduce the carat weight of the gem to 0, the gem is reduced to dust.
Gemcutting DC
| Gem Quality | Cutting DC |
|---|---|
| Chipped | 5 |
| Flawed | 15 |
| Regular | 20 |
| Flawless | 25 |
| Perfect | 30 |
Credits
Designed by d'Artagnan on DMs Guild, /u/dArtagnanDnD on reddit, or dArtagnanDnD on patreon and dArtagnanDnD on Twitter.
- Made with "GM Binder".
- Made with reference and for use with Dungeons and Dragons 5th Edition, created by Wizards of the Coast.
The Cutting Result
No two gems are flawed in the same way. So succesfully cutting a gem will result in one or more smaller gems of higher quality. Roll on the Sucessful Cut table below.
If you failed the check, roll on the Failed Cut table below. If you have not failed by 5 or more, you do not get a lower quality gem, regardless of what the result says.
Successful Cut
| d100 | Result |
|---|---|
| 1 | You cut out a minor imperfection at the edge. The gem's quality improves and only loses 1d4 carats. |
| 2 - 10 | You cut out several imperfections. The gem's quality improves and loses 1d6 carats. |
| 11 - 30 | You have to cut the gem into many smaller pieces. You get 1d10 + 1 equally sized gems of higher quality. |
| 31 - 45 | You cut out a third of the gem. You get one gem of higher quality and a second smaller gem of the original quality. |
| 46 - 55 | You cut out a complicated flaw. You get 1d4 + 1 equally sized gems of higher quality. |
| 56 - 70 | You cut out two thirds of the gem. You get one gem of higher quality and a second bigger gem of the original quality. |
| 70 - 90 | You cut the gem into two equally sized gems, only one of which is of higher quality. |
| 91 - 99 | You cut the gem into two pieces of higher quality. The smaller gem is 1d4 tenths of the original gem. |
| 00 | You cut the gem along an imperfection along the middle of it into two equal parts of higher quality. |
Failed Cut
| d6 | Result |
|---|---|
| 1 | Your gem loses 1d10 carats. |
| 2 | Your gem loses 3d6 carats. |
| 3 | You smashed the gem into 1d4 smaller pieces. |
| 4 | You smashed the gem into 1d10 smaller pieces. |
| 5 | You broke the gem into two smaller pieces, only one is of lower quality. |
| 6 | You've only scratched the gem. It does not lose any weight. |
Magicked Gemstones
Gemstone are frequently used in magic from storing spells to being used to cast them. So, you are not the first pracitioner to consider using spells like mending, make whole, or fabricate to either fix their mistakes or to fuse several gems into a larger one. But fusing crystals into one another does not come without its own complications, nor is it ever perfect.
You can use mending to fuse two gemstones together. The resulting gem always has a quality one step lower than worse gem to a minimum of quality of Chipped.
You can use make whole to fuse more than two gemstones or even gem dust together. The quality of the result is determined the same as for mending, except using gem dust in any capacity always results in a gemstone of Chipped quality.
The fabricate spell can create any gemstone you can imagine, but is limited by your skills as a jeweler. Make a jeweler's Tools check using your casting ability. The quality of the resulting gem is determined by the highest DC you beat. Failing to beat the DC of Chipped, or not being proficient in jeweler's tools results in a worthless rock being created.
Uncut Gemstones
Occasionally, you will encounter an uncut gemstone. These gemstones have a quality, just like their cut counterparts, but are worth half as much as a cut gem of that size.
Gem Dust
When you lose mass from a gem, it is not lost. Your gem offcuts turn into gem dust, a common material component of many spells.
For the purposes of casting spells with gem dust, you calculate its value by weight compared to it's cost as a Flawless gemstone. Nonspellcasters generally have no use for gem dust. If they do buy it, they will buy it at half the cost of a Chipped gemstone of the same weight.
Buying gem dust for spell casting, costs the same as normal, however.
Growing Gemstones
With the correct understanding of mineralogy, and the correct solutions, you can take your practically worthless gem dust and grow your own gemstones.
If you are proficient with Alchemist's Supplies, you can create a solution to grow gemstones with an hour of time and 50 gp of materials. Over time, you will grow an uncut gemstone. This process is slow, however, and the gemstone will grow at the rate of 1 carat per day.
Once you are done, make an Intelligence (Alchemist's Supplies) check. The quality of the resulting gem is determined by the highest DC you beat. You add any bonuses to the roll such as those granted by Fox's Cunning if you were under its effects when you created the solution.