Understone: Gemstone Mines

Dig, deduce, discover gems

Free · In‑App Purchases · Designed for iPad. Not verified for macOS.

Read the clues. Save your stamina. Discover real geological districts in a mineral-deduction adventure with a hands-on practice guide. Every dig is a decision. Understone combines weighted grid clues with a dwarf miner’s expedition across eight real-world geological settings. Read the neighboring totals, plan your stamina, collect beautiful mineral specimens and choose the right moment to upgrade. A number adds the mining costs in the eight surrounding cells. Opening a gem spends stamina immediately; collecting it earns experience. Food restores your stamina, while upgrades wait for your decision. Later districts introduce lethal mines, marked by clear neighboring warnings. Explore 24 freshly generated floors across basalt geodes, fluorite veins, pegmatites, marble, nephrite contacts, emerald veins, kimberlite pipes and gem-bearing gravels. District briefings introduce local specimens; field reviews reveal their original distribution. Build a mineral journal with formation facts and research sources as you discover them. The journal covers 29 collectible specimen names, including mineral species, groups, varieties and nephrite aggregates. Tap a collected specimen in the collection bar to open its entry. Visit camp after each district to appraise your finds and choose supplies or long-term equipment. Higher purchase tiers and a measured growth curve keep resource decisions meaningful. • Learn by tapping a small interactive practice field. • Continue a saved expedition on this device. • Adjust music and effects separately. • Play in English, Simplified Chinese or Traditional Chinese. • Compare completed expeditions in local scores. The opening district’s three floors and first camp are free. A single in-app purchase unlocks all remaining field sites, with no subscription. The price is displayed in your App Store currency. Restore purchases is available. No app account is required.

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The developer, Joey Zhou, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .

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    Information

    Seller
    Joey Zhou
    Size
    34.8 MB
    Category
    Puzzle
    Compatibility
    Requires iOS 17.0 or later.
    • iPhone
      Requires iOS 17.0 or later.
    • iPad
      Requires iPadOS 17.0 or later.
    • Mac
      Requires macOS 14.0 or later and a Mac with Apple M1 chip or later.
    • Apple Vision
      Requires visionOS 1.0 or later.
    Languages
    English and 2 more
    • English, Simplified Chinese, Traditional Chinese
    Age Rating
    13+
    • 13+
    • Learn More
    • Frequent
      Guns or Other Weapons

      Infrequent
      Cartoon or Fantasy Violence
    In-App Purchases
    Yes
    Copyright
    © 2026 IdeaSpike. All rights reserved.
  • Privacy Policy

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