Glow stone is a block which can provide light and can be placed underwater.
To make Glowstone, you need to enter into Nether to get Glowstone Dust and then have to use the Crafting Table. Please follow the following steps to make a Glow stone.
Glow Stone Dust
In order to make glow stone, the basic item you need to find and get is glow stone dust. Enter the Nether and mine glow stone using your pickaxe to get at least four glow stone dust.
Now you can craft a glow stone using the crafting table. Go towards crafting table and open up 3*3 crafting grid to add four glow stone dusts in four adjacent cells. You will get a Glow stone in the right-side box of the crafting table. Add this stone in your “ready to use” stock.