---
name: "Heartstone"
mana_cost: "{3}"
cmc: 3
type_line: "Artifact"
colors: []
color_identity: []
keywords: []
set: "STH"
set_name: "Stronghold"
collector_number: "134"
rarity: "uncommon"
artist: "John Matson"
oracle_id: "8f8ebf49-37c5-4da0-9cee-84ad22ab5d37"
canonical_url: "https://avascry.com/printing/heartstone-sth"
legalities:
  commander: "legal"
  standard: "not_legal"
  modern: "not_legal"
  pioneer: "not_legal"
  legacy: "legal"
  vintage: "legal"
  pauper: "not_legal"
  penny: "not_legal"
---

# Heartstone
- **Mana Cost:** `{3}` (CMC: 3)
- **Type:** Artifact

## Oracle Text
Activated abilities of creatures cost {1} less to activate. This effect can't reduce the mana in that cost to less than one mana.

> *"Finding a true heartstone is even harder than finding a true heart."
—Hanna*

## Top 4096-Dim Neural Synergies
1. [Training Grounds](/printing/training-grounds-tle.md) — Enchantment
2. [Agatha of the Vile Cauldron](/printing/agatha-of-the-vile-cauldron-pwoe.md) — Legendary Creature — Human Warlock
3. [Helm of Awakening](/printing/helm-of-awakening-plst.md) — Artifact
4. [Power Artifact](/printing/power-artifact-prm.md) — Enchantment — Aura
5. [Biomancer's Familiar](/printing/biomancers-familiar-prna.md) — Creature — Mutant
6. [Stone Calendar](/printing/stone-calendar-drk.md) — Artifact

## Printing Details
- **Set:** Stronghold (STH) #134
- **Rarity:** Uncommon
- **Artist:** John Matson
- **Total Printings:** 12 across all historical editions

## Format Legalities
Commander: `legal` | Standard: `not_legal` | Modern: `not_legal` | Pioneer: `not_legal` | Legacy: `legal` | Vintage: `legal` | Pauper: `not_legal` | Penny: `not_legal`