Oremageddon

Oremageddon is a Minecraft mod created by Homicidal_Lemon. It is themed around underground exploration and new ores, mostly focused in the Overworld. It is designed to make vanilla progression smoother, adds 7 new balanced armor and tool sets, and introduces 10 new cave biomes. New mobs and structures are currently under development.

New Ores
Oremageddon currently adds 12 new ores to the Overworld, 2 of which also generate in other dimensions, and 1 ore to the Nether.

Copper Ore
Copper Ore attempts to generate at any height below y=128 in veins of up to 8, more frequently the closer it is to sea-level. It can be smelted to create a Copper Ingot, which can create tools and armour between stone and iron, among other things.

Bone Fossil Ore
Bone Fossil Ore attempts to generate 15 times per chunk below y=128 in veins of up to 3. When mined, it drops 1-3 Bones and 0-2 experience. It also generates in the floors of Silverfish Caves uncommonly.

Shell Fossil Ore
Shell Fossil Ore attempts to generate 1 times per chunk below y=128 in veins of up to 3. It requires Silk Touch to not be destroyed. When smelted, Shell Fossil Ore becomes a Shell Fossil, which can either be used as a brewing ingredient to brew Fortitude Potions (as of the upcoming v1.08) and can be used to craft Water Breathing Charms.

Silver Ore
Silver Ore attempts to generate 3 times per chunk below y=32 in veins of up to 9. It can be smelted to create a Silver Ingot, which can be used to craft roughly iron-tier tools and armour but which's primary purpose is Electrum.

Sulphur Ore
Sulphur Ore attempts to generate below y=16 in veins of up to 3, more frequently the deeper it is. When mined, it drops 1 Sulphur Crystal and 1-5 experience. Sulphur Crystals can be used to craft Gunpowder, Dye-able Sulphur Lamps and used as a brewing ingredient to make Energy Potions (as of the upcoming v1.08).

A Netherrack variant also generates in the Nether.

Sapphire Ore
Sapphire Ore attempts generates 1 time per chunk below y=16 in veins of up to 8. When mined, it drops 1 Sapphire and 4-8 experience.

Amethyst Ore
Amethyst Ore attempts to generate 1 time per chunk below y=16 in veins of up to 8. When mined, it drops 1 Amethyst and 4-8 experience.

Ruby Ore
Ruby Ore attempts to generate 1 time per chunk below y=16 in veins of up to 8. When mined, it drops 1 Ruby and 4-8 experience.

Cave Fruit Ore
Cave Fruit Ore generates commonly in Overgrown Caves. When mined, it drops 1-3 Cave Fruit and 0-2 experience.

Edenite Ore
Edenite Ore generates uncommonly in Overgrown Caves. When mined, it drops 1 Edenite and 4-8 experience.

Cryolite Ore
Cryolite Ore generates uncommonly in Overgrown Caves. When mined, it drops 1 Cryolite and 4-8 experience.

Celestial Stone
Celestial Stone attempts to generate 50 times per chunk between y=100 and y=128 in veins of up to 3. When mined, it drops 4-5 Stardust and 3-11 experience.

An End Stone variant also tries to generate 50 times per chunk below y=140 in the End.

Glowing Obsidian
Glowing Obsidian attempts to generate 1 time per chunk below y=32 in veins of up to 33 in the Nether. When mined, it drops 1 Obsidian. Glowing Obsidian cools down over time into normal Obsidian, which is significantly slower to mine.