The Spelunker Update
The Spelunker Update expands Minecraft's underground with new cave biomes, metals, alloys, gems, traversal tools, utility gear, and cave-focused crafting systems. Explore fungal grottos, magma vaults, marble caves, and crystal caverns while building new loadouts around foundry alloys, socketed miner's helmets, tonics, rope, and deeper cave resources.
Overview
The Spelunker Update is a cave-expansion mod built around the idea that the underground should feel like a real progression path instead of just a place to grab ore and leave.
It adds new cave biomes, new metals and gems, new crafting systems, new utility equipment, and a stronger sense that different underground regions have their own identity. Instead of caves being mostly the same stone with different ores mixed in, this mod aims to make exploration itself feel rewarding.
Main Features
New Cave Biomes
The underground now includes several distinct biome types with their own terrain, mood, and resources.
Marble Caves are large marble-heavy cavern regions that feel cleaner and brighter than normal underground stone.
Crystal Caverns are bright, prismatic cave systems filled with marble, crystal spikes, and glowing stone.

Magma Vaults are deep volcanic chambers full of cinder rock, ash, scorched dripstone, and lava-lit ruins.

Fungal Grottos are giant mushroom caverns with mycelium mud, bioluminescent moss, glowcaps, fungal overgrowth, and huge mushrooms.

New Metals, Gems, and Materials
The mod adds new overworld metals and underground gem materials that support both progression and utility.
Tin, Nickel, and Silver generate as new ore lines in the overworld.

Topaz, Ruby, and Sapphire appear through special cave features rather than simple ore veins.
Marble, Prismatic Stone, Cinder Rock, and other biome stones provide large new building palettes.
Foundry and Crucible Alloying
Alloys are produced through a two-block structure:
Crucible stores lava as fuel
Foundry processes alloy recipes above it
Current alloys include:
Bronze
Electrum
Invar
Rose Gold
This system is meant to give underground materials a stronger crafting identity than just "smelt ore into ingot."
Cave Utility Gear
A large part of the mod is focused on gear that helps with exploration rather than only combat.

Examples include:
Bronze Compass for depth reading
Miner's Helmet with socketed gem effects
Prospector's Lens for ore scanning
Torch Launcher for ranged torch placement
Rope and Rope Bundles for vertical cave travel
Bronze Shield and Electrum Bow for more specialized equipment
Armor Upgrades
Iron armor can be upgraded through smithing paths with different roles:
Nickel Plating for durability and toughness
Silver Lining for wither protection
Rose Gold Filigree for a more arcane, luck-focused route
Tonics and Exploration Effects
Several cave-focused consumables give short-term exploration advantages.
Spelunker's Brew
Dangersense Tonic
Miner's Tonic
These are meant to support scouting, mining, and cave survival rather than replace normal progression.
Notes
- Best experienced on a fresh world so the new cave biomes and underground features generate naturally.
- The mod is designed around the overworld underground rather than replacing vanilla progression entirely.
- Texturing is hard i aint that good at art
Plans
- Create a seperate ruby/sapphire/topaz block for geodes versus a compressed block
- Better textures ???
- More alloys
- Charred Bone (fossil?) structure
- More to come
- Achievements, Gamerules, and Customization options