This is a mod that adds various things:
Block: Blue cobblestone: You can find it in caves rarely, or you can craft it with blue dye and cobblestone or you can craft it with 9 blue cobblestone dust
Block: Smooth blue cobblestone: Decorative block, you can craft it with blue cobblestone and stonecutter.
Block: Bricks of blue cobblestonee: Decorative block, you can craft it with blue cobblestone and stonecutter or you can craft it with four blue cobblestone bricks.
Block: Blue cobblestone light: Decorative block, it also makes light, you can craft it with blue cobblestone dust and prismarine cristals
Item: Dust of blue cobblestone: You can craft it with one block of blue cobblestone.
Item: Brick of blue cobblestone: You can craft it with smelting blue cobblestone dust.
Tool: Blue cobblestone sword: Sword that deal a lot of damage but is not have much resistance
Tool: Blue cobblestone knife: Sword that deal a lot of damage but is not have much resistance
Also you can craft the warden egg