How to build a Nether portal in Minecraft (and link two portals)
Their chests can hold 1 or 2 Obsidian, Flint and Steel and Fire Charges.

Flint is a sharp stone that gravel sometimes drops instead of itself.
It cannot be crafted; it can be found in chests.
Breaking Gravel gives flint now and then, more with Fortune. It crafts Flint and Steel, arrows and the fletching table, and fletchers buy it.
This item has no crafting recipe.
Their chests can hold 1 or 2 Obsidian, Flint and Steel and Fire Charges.
one Flint, one Stick and one Feather craft 4 of them, and skeletons drop more.
It can be found as loot in Village and Ruined Portal. Sold by Villager: Fletcher (Novice). Bought by Villager: Fletcher (Apprentice), Leatherworker (Apprentice), Toolsmith (Journeyman), Weaponsmith (Journeyman).
It makes flint and steel and arrows. It is an ingredient in 3 recipes, made at the Crafting Table; for example Arrow, Fletching Table and Flint and Steel.
Gravel (10%, with Fortune III 100%).