You will go through three different phases of crafting. First things first you'll have to craft Spectrite Shards. To craft them, you need 1 Diamond, 1 Iron Ingot, 1 Gold Ingot, 1 Glass Block ( not stained ), 1 Emerald, 2 Lapis Blocks and 2 Redstone Blocks. After you got 4 Spectrite Shards, you have to place them in a 2x2 Area anywhere in your Crafting Table to craft 1 Raw Spectrite Gem . To polish it/ make it shiny you'll have to surround the Raw Spectrite Gem with 8 Glass Blocks ( not stained ). Your final result will be a Spectrite Gem.
