Krikke's Mod

Crystals spawn randomly across the world in deep-layer caves. These crystals can be used to create Crystal Armor and a Crystal Shield.
Blood Crystals spawn randomly across the nether. These can be used to create Vampyre Armor.

A special crafting station called the Extractor can be crafted and interacted with to extract certain items from their resources.

Pearls can be extracted from Oysters using the Extractor.

These pearls can be used to create the Crystal Shield or some really cool Vanity Gear, but beware, Pearls are really rare.

Another cool addition is the fact that you can extract Gravel with the Extractor with a 1/3 chance to extract Flint. This way you don't need to dig for Flint anymore (but you still need fuel).

Fossils spawn randomly underground in Stone. These can be extracted using the Extractor to get some random items like Smooth Stone, Bones etc.

Jellyfish are new passive mobs found in the ocean. When you come too close, they'll try to sting you to death. They can drop Jelly which can be crafted into a Block of Jelly, a pink variant of the Slime Block.

Graves spawn across the world with a Treasure beneath which can be extracted for lots of goodies!

**All additional information (such as crafting recipes) can be found on the minecraft forums here.