Visual concept for Starjewel

Five Gemstone Spells 2

Back in my Enchantment Under the Sea post, I created a spell called gemscribe. It got me thinking about other interesting things to do with crystals in spellcasting (as opposed to, say, making ioun stones with them). I haven’t figured out where any of these might get polished up (get it, it’s gems) and published.

Ruby Ember

6th-level transmutation – sorcerer, wizard

Casting Time: 1 minute
Range: Touch
Components: V, S, M (a ruby worth at least 500 gp)
Duration: 8 hours

The ruby that you touch while you cast this spell is transformed into a receptacle for fire spells. Choose up to three spells of up to third level that you know that deal fire damage.

During the spell’s duration, while the ruby is in your possession, you have resistance to cold damage. You can cast fire bolt, and when you do, you deal an additional 1d10 fire damage on a hit. While you are touching the ruby, you can use your action to cast one of the spells you chose during the casting of this spell. You can use this action three times.

When the spell’s duration ends, you can choose to extend its duration to 24 hours if the ruby is in your possession. If you do, the ruby is consumed when its duration expires or when it leaves your possession.


3rd-level transmutation – cleric, druid, paladin

Casting Time: 1 minute
Range: Touch
Components: V, S, M (a moonstone worth at least 100 gp)
Duration: 8 hours

The moonstone that you touch while you cast this spell glows with a powerful, steady light. It provides bright light to a radius of 30 feet and dim light for an additional 30 feet, even in areas of magical darkness created by spells of 3rd level or lower.

During the spell’s duration, one creature touching the moonstone gains resistance to necrotic damage and can cast sacred flame. The creature uses the same spellcasting ability score that you used to cast this spell. Once per round when they roll the maximum value on one of the spell’s damage dice, they roll another d6 and add it to the result.

When the spell’s duration ends, you can choose to extend its duration to 24 hours if the moonstone is in your possession. If you do, the moonstone is consumed when its duration expires.

Heart of Amethyst

9th-level abjuration – sorcerer, warlock, wizard

Casting Time: 1 day
Range: Self
Components: V, S, M (an amethyst worth at least 5,000 gp, which the spell consumes)
Duration: Permanent

When you cast this spell, you replace your heart with a massive amethyst or amethyst geode. It is phenomenally painful and draining, and you suffer a -4 penalty to all attacks, ability checks, and saving throws afterward. This penalty decreases by 1 each time you take a long rest.

For the spell’s duration, you don’t age, you don’t take additional damage from critical hits, and you gain 25 temporary hit points when you finish a long rest. When you would be reduced to 0 hit points, you have 1 hit point instead, and you can’t use reactions until you haven’t taken damage for 1 minute. You are immune to power word kill.

This spell can’t be dispelled while you have more than 1 hit point. While you have 1 hit point, the spell can only be dispelled by a dispel magic cast using a 9th-level spell slot while the caster is touching your body.

Dreaming Prism

2nd-level divination (ritual) – bard, cleric, druid, sorcerer, warlock, wizard

Casting Time: 1 action
Range: Touch
Components: S, M (a rose quartz worth at least 25 gp)
Duration: Concentration, up to 8 hours

The rose quartz that you touch while you cast this spell allows you to observe the dreams of one creature within 5 feet who is asleep and able to dream. If the creature you are observing is the target of a dream spell while you are within 5 feet, you learn the name of the spell’s caster, and you can give the target advantage on any saving throw they make against dream.

If you observe a creature’s dreams for at least 1 hour, you learn its personality features, the nature of any curses it currently suffers, and one thing it fears. If the creature is willing, you can also observe one person, place, or thing from its memory. You gain the same degree of familiarity with the person, place, or thing that the creature has.

Crystal Seed

2nd-level conjuration – sorcerer, wizard

Casting Time: 1 action
Range: 30 feet
Components: V, S, M (a quartz worth at least 10 gp, which the spell consumes)
Duration: Concentration, up to 1 minute

You hurl a tiny piece of quartz at a creature you can see. The creature makes a Dexterity saving throw; on a failure it takes 3d10 piercing damage, and for the duration of the spell, when you cast a spell using a spell slot of 1st level or higher, it takes 3 points of damage per level of the spell slot expended, as crystal vines grow through its body. On a successful saving throw, the target suffers half damage and no further effect.

At Higher Levels. When you cast this spell using a spell slot of 3rd level or higher, you can choose an additional target for each level of the spell slot above 2nd.

Design Notes

The core idea behind ruby ember is the phrase “flame cascade” that popped into my head and lived there rent-free for awhile. I like the image of this gemstone roiling with barely contained fire. Trading one 6th-level slot for three more fireballs is me being a conservative on power level, but it’s not my fault that fireball breaks the power curve on spells.

Starjewel is, you know, the Light of Eärendil but in spell form rather than as a magic item. Also I thought it would be fun to have a spell that did something nice for sacred flame.

Heart of amethyst is an on-the-nose reference to Dust to Dust. Amethyst was our top-end stone for value and magical uses – it was a Whole Thing. Anyway, replacing your heart with a gemstone sounded cool to me, even if it’s a bit more of a villain move than a PC one.

Dreaming prism could certainly be justified without the gemstone. I just, you know, don’t wanna. I think it’s cool to imagine the spellcaster using the rose quartz like a lens to watch what’s going on in the sleeper’s dream.

Crystal seed is because the image of crystalline vines or trees is another thing that has lived rent-free in my head for… oh. A decade now. Goodness, how time flies.

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2 thoughts on “Five Gemstone Spells

  • Craig W Cormier

    Gotta say, loving these. Any spell that has an expensive component that actually plays a part in the spell’s function is just *chef’s kiss*. Having a higher-level spell grant access to thematically related cantrips and lower-level spells is really a cool idea.

    A couple of clarifications:
    – Should Ruby Ember qualify that the spells it allows you to cast are cast as if using their lowest spell slot (you know, if someone uses it for something other than Fireball). Or maybe it should say that it is cast as if using a 3rd level slot since all the low-level fire spells I can think of have an upcasting option anyway.

    – At least if I am reading this correctly, Starjewel doesn’t dispel magical darkness, just suppresses it for the duration, which I really like. The confusing part is about the spellcasting ability score for Sacred Flame. Does the person who has the jewel calculate their own spellcasting bonus using their own score? Or do they use the caster’s bonus and score? I think it’s the former, which I also like.

    – Heart of Amethyst appears to make you unkillable via normal means? Understanding that it is a 9th level spell and should do bonkers stuff, it still feels like the second paragraph is missing a qualifier on the ability to be reduced to 1 hit point instead of 0. The fact that you can’t take reactions for 1 minute afterward made me think that perhaps this was supposed to be a reaction effect, thus being self-limiting.

    – I have no comments on Dreaming Prism other than to say that I am immediately stealing it for my campaign because I make extensive use of dreams throughout.

    – Crystal Seed is a fun spell, especially for a caster that usually focuses on buffs/debuffs. Allowing them to do damage while casting spells that otherwise wouldn’t is a nice treat. Just gotta make sure the player actually keeps track of the spell, but that is their responsibility as the spellcaster.

    Again, great stuff.

    • Brandes Stoddard Post author

      I’m so glad you like them! And I just want to say how much I appreciate that you always have constructive feedback and take time to share it. =)

      Ruby Ember – Fireball is the “best” spell here by such a wide margin that I honestly don’t care if you use a 3rd-level Burning Hands or whatever. If you see a worrying use case that I’m missing, lemme know?

      Starjewel – my thinking was that you calculated by the holder’s spellcasting ability score, but if you got it from a cleric it used Wisdom, Charisma if from a bard (Magical Secrets) or paladin, etc. Not really game-breaking either way, considering that it’s a 6th-level spell on the line.

      Heart of Amethyst – I don’t intend for the life-saving power of the magic to cost a reaction, because then it lasts for the duration of one attack and that’s not getting the job done for me. The reaction denial is more to represent “you’re staggered and moving slowly, and you can’t counterspell that incoming dispel magic.” But one of my readers in FB has pointed out that I’ve managed to make something that is OP relative to lichdom, so I’ll be reworking this somewhat.

      Dreaming Prism – glad you like it! Steal it with gusto.

      Crystal Seed – yeah, it’s a little fiddly on the data tracking, but I’m not sure it’s meaningfully worse than the positional tracking of flaming sphere in mental load. The mechanic here is an oblique sign that I’ve been playing too much Slay the Spire lately. 😉