More Coral
Nathan.S

Adds coral in more colors.

golden lava
GigaByte

add golden lava

Noriel Sylvire's Minerals Core Modpack
Noriel_Sylvire

An API for automatically registering recipes, nodes and ore generation.

Unstable Caves
M BLOC

Some stones may cave in if punched, making underground expeditions more risky.

treasures
ademant

Treasure nodes with useful items

Sticks Stones
MikeRedwood

Makes Sticks from leaves and scatters small stones

Spawn redo
cathaya7d4

Drop-in replacement for default/spawn for more third-party biomes

Trucraft
mt-mods

An alternative crafting system done entirely in the world.

Dirt Tunneler
Neuromancer

Makes dirt deeper and you can tunnel through it just by walking through it. Press spacebar/shift to tunnel upward/downward with auto placed ladders.

Obdy
Sires

Adds some pretty OP tools :)

Underground Survival Lighting
Arkatron

If you like underground light in survival, use this mod, it can help that.

Mud
Blocky Player

Adds stylish mud blocks and even blocks you can walk through. Setup traps, secret rooms and much more!

Silver
Jackknife

adds silver ore and tools