Aluminum (Al) is a metal, and it doesn't form "compounds" in the way that elements like carbon or oxygen do. However, it readily forms ionic compounds with other elements. Here's a breakdown:

Common Aluminum Compounds:

* Aluminum Oxide (Al₂O₃): This is a very common compound, found naturally as the mineral corundum. It's used in ceramics, abrasives, and even as a base for gemstones like ruby and sapphire.

* Aluminum Hydroxide (Al(OH)₃): Used in antacids, water treatment, and as a component of some fire retardants.

* Aluminum Chloride (AlCl₃): Used as a catalyst in chemical reactions and as a component of some deodorants.

* Aluminum Sulfate (Al₂(SO₄)₃): Used in papermaking, water treatment, and as a coagulant in various processes.

* Aluminum Nitrate (Al(NO₃)₃): Used in explosives, as a mordant in dyeing, and in some fire extinguishers.

* Aluminum Phosphate (AlPO₄): Found in some fertilizers and used in dental cement.

Note: These are just some examples. Aluminum forms a wide variety of compounds due to its ability to lose three electrons and form a +3 cation.

Remember: Aluminum itself is an element, not a compound. These are compounds *containing* aluminum.