Namaste Mother Nuggets!
In Mystic Times, every gemstone holds a little magic, and the meaning people have given that stone for centuries in the real world shapes what it does. An agate guards you. An amber holds onto life. A diamond pulls someone back from the brink. Slot one into your gear, use it once, and the magic is gone until the next full moon.
These go hand in hand with my runestones post. Runes and gems share the same sockets, and they’re the two halves of the same folk-magic system. Both come from the Mystic Times Campaign Guide.
So tell me: what’s the most valuable gem your party has ever found, and did they sell it or keep it? Let me know in the comments.
How Gemstones Work
If you’ve read the runes post, a lot of this will feel familiar. If not, here’s the whole system.
- One use, then it’s dark. Each gemstone can be activated once. After that its magic is spent.
- Recharge it under a full moon. Unlike runes, which have to be re-inscribed, a gemstone can be recharged with a cleansing ritual performed on a full moon. It needs someone with some skill in spellcraft or arcane lore. That means a spent gem can take up to a month to come back, which is a lovely bit of tension for a campaign.
- Quality matters. The better the stone (clearer, better cut, more complex), the stronger its magic.
- Sockets are everywhere. Ordinary weapons, armour and gear often come with empty sockets, and almost any smith can set a gem or rune into one.
- Real magic wins. Enchanted items overpower the low-level folk magic of gems. A gem socketed into a magic sword won’t work; the sword’s own magic drowns it out.
The Gemstones
The prices are straight from the Campaign Guide, in gold crowns (call them gold pieces if your game prefers). Like my other resource posts, they sit on a baseline of 0.1 gold for one day’s work by a farmer or labourer. So even the cheapest magic gem is around 200 days’ wages. This is not pocket change. This is the family heirloom.
Minor Gems: 20 gold
| Gem | Rarity | Effect when activated |
|---|---|---|
| Agate | Uncommon | A bonus to your defence against the next attack you receive. |
| Amber | Uncommon | Stabilises a dying person. |
| Aquamarine | Uncommon | A bonus to the next saving throw you make. |
| Jasper | Uncommon | Automatically pass a balance check. |
| Moonstone | Uncommon | A bonus to any roll needed for a spell. |
| Onyx | Uncommon | A bonus to your next concentration check. |
| Tiger eye | Uncommon | A bonus to your next physical attack. |
| Zircon | Uncommon | A bonus to your next spellcraft check. |
Lesser Gems: 50 gold
| Gem | Rarity | Effect when activated |
|---|---|---|
| Amethyst | Uncommon | A bonus to resist the next spell cast on you. |
| Bloodstone | Uncommon | Cast remove disease, as if from a scroll. |
| Citrine | Uncommon | A bonus to the next skill check you make. |
| Garnet | Uncommon | Cast cure light wounds, as if from a scroll. |
| Lapis lazuli | Uncommon | Automatically pass a sense motive or insight check. |
| Malachite | Uncommon | Force an opponent to reroll an attack or spell. |
| Obsidian | Uncommon | Cast remove curse, as if from a scroll. |
| Turquoise | Uncommon | Understand all languages for the next 10 minutes. |
| Unakite | Uncommon | Remove the effects of a poison. |
Greater Gems: 100 gold
| Gem | Rarity | Effect when activated |
|---|---|---|
| Jade | Rare | Reroll an attack, skill check or save. |
| Opal | Rare | Maximise the next spell you cast. |
| Pearl | Rare | Breathe water for the next hour. |
| Peridot | Rare | A morale bonus to every save the party makes for 1 hour. |
| Quartz | Rare | Double the bonus, damage or effect of the next spell you cast. |
| Topaz | Rare | Double the duration of the next spell you cast. |
Precious Gems: 500 to 1,000 gold
| Gem | Rarity | Price | Effect when activated |
|---|---|---|---|
| Emerald | Very rare | 500 gp | Cast charm person, as if from a scroll. |
| Ruby | Very rare | 500 gp | Cast cure moderate wounds, as if from a scroll. |
| Sapphire | Very rare | 500 gp | Replenish one spell slot for each level of spell you can cast. |
| Diamond | Very rare | 1,000 gp | Cast cure serious wounds, as if from a scroll. |
| Jacinth | Very rare | 1,000 gp | Negate the next attack made against you. |
A couple of favourites. Malachite is fantastic in the hands of a sneaky player: one perfectly timed “nope, roll that again” can turn a boss fight. And jacinth is the gem every bodyguard dreams of. It doesn’t heal you, it just makes the worst hit of the night simply not happen.
Optional Rule: Gem Quality
The Campaign Guide says better stones hold stronger magic. If you want that at your table, here’s a simple way to do it:
| Quality | Price | Effect |
|---|---|---|
| Flawed | Half price | Half the bonus, or a 50% chance the effect fizzles |
| Standard | Listed price | As listed |
| Flawless | Triple price | Double the bonus, or the effect works twice before going dark |
Flawed gems are great things to stock in a dodgy market stall. Flawless ones make wonderful quest rewards.
At the Table
Here’s how I’d run these in a few systems. These are my quick conversions, so adjust to taste.
At the Table
OpenD6
- “A bonus” gems (agate, aquamarine, moonstone, onyx, tiger eye, zircon, amethyst, citrine): +1D to the matching roll.
- “Automatically pass” gems (jasper, lapis lazuli): no roll needed.
- Healing gems: garnet heals one wound level, ruby two, diamond three. Amber stabilises a mortally wounded character.
- Jade: reroll one roll, including the Wild Die.
- Malachite: an opponent rerolls one attack or spell.
- Opal, quartz, topaz: +2D to your next spellcasting roll, or double the spell’s damage or duration, at the GM’s call.
- Sapphire: +2D to your next two spellcasting rolls.
- Jacinth: negate the next attack against you, whatever the roll.
At the Table
4 Against Darkness
Whenever your party finds a gem as treasure, roll a d6 to see whether it holds magic:
| d6 | Gem | Effect |
|---|---|---|
| 1–2 | Just a pretty stone | Sell it as normal. |
| 3 | Tiger eye | One character gets +1 on one Attack roll. |
| 4 | Agate | One character gets +1 on one Defence roll. |
| 5 | Garnet | One character regains 1 Life between rooms. |
| 6 | Jade | Reroll any one die, once. |
Magic gems are spent once used, and there’s no full moon in the dungeon, so treat them as one-shot items.
At the Table
Warrior Heroes: Adventures in Talomir
Gems are Single Use (S) magic items, just like potions and scrolls.
- Agate: treat your armour as one level higher on the Damage Table for the next hit.
- Tiger eye: +1d6 in your next melee.
- Moonstone or zircon: counts as a Level 1 Magic Casting Item for one Spell.
- Amethyst: counts as Magic Resistant against the next Spell.
- Amber or garnet: take the Healing Test as if a Rep 4 Healer were treating you. Ruby: as a Rep 5 Healer. Diamond: an Out of the Fight character returns to the fight at −1 Rep, no roll needed.
- Jade: reroll one test.
- Malachite: an opponent rerolls one test.
- Peridot: your whole band gets +1d6 on Will to Fight Tests for one Encounter.
- Sapphire: a Caster recovers all spent Magic Power.
- Jacinth: ignore the next hit that would knock you Out of the Fight or Obviously Dead.
- Value in Increasing Rep d6: minor and lesser gems (1), greater gems (2), emerald, ruby and sapphire (4), diamond and jacinth (8). The first time you use one, roll 2d6: on a 12 it’s cursed, and on a 3 it’s worthless glass.
At the Table
D&D 5e
- “A bonus” gems: add 1d4 to the matching roll (agate to AC against one attack, aquamarine to a save, tiger eye to an attack roll, moonstone or zircon to a spell attack or check).
- Amethyst: advantage on the save against the next spell targeting you.
- Healing gems: garnet casts cure wounds at 1st level, ruby at 2nd, diamond at 3rd. Amber stabilises a creature at 0 hit points.
- Jade: reroll one d20 and use either result.
- Malachite: as a reaction, force a creature to reroll one attack roll.
- Opal: maximise the damage or healing dice of the next spell you cast.
- Sapphire: regain expended spell slots with a combined level up to half your character level (rounded up).
- Jacinth: as a reaction, an attack that would hit you misses instead.
Over to You
Gems and runes are my favourite kind of magic to hand players, because they force choices. Do you burn the ruby now, or save it for the fight you know is coming? Do you sell the diamond and buy a house, or keep it for the day your fighter goes down?
If you haven’t seen it yet, the runestones post has all 24 runes that slot into the same sockets.
Which gem would you most want in your boot? Tell me in the comments.
Ciao for now.
Use it at your table: The game rules and mechanics in this post are shared under a Creative Commons Attribution-NonCommercial 4.0 licence. Use them, tweak them and share them for your own games.
Product Identity: The names of characters, places, factions and deities (everything that makes it Mystic Times) are Product Identity of Arjade Productions and aren’t covered by that licence. They’re yours to use at your table, but not to publish.
(Note: This post was created adapting my published books using tools which may include elements of artificial intelligence.)