Forked to fix some bugs, permission from the original author is in the screenshot below. (Permission also can be found on the original page at https://www.curseforge.com/minecraft/mc-mods/progressive-core under the spoiler "What's going on lately? (I quit modding)"

 

Progressive Core is a rather simple but big mod which adds a variety of valuable ores, tools, weapons, armor, accessories and machines to the game.

 

The ore system is as the mods name suggests progressive and each ore/alloy has a certain tier.

 

Tier 0: Wood

Tier 1: Stone, Flint, Leather

Tier 2: Copper, Tin, Iron

Tier 3: Bronze, Tungsten

Tier 4: Steel, Obsidian

Tier 5: Hellsteel

Tier 6: Titanium

Tier 7: Mithril, Orichalcum, Adamantite

 

To get to the next tier you need ores/alloy from the previous tier.

 

Ore generation, tool and armor stats as well as pretty much everything else is configurable in your config file.

 

For the full original description see the original page.