Depending on whether you need a small jar for polishing or bulk quantities for sandblasting, you can find aluminum oxide at the following locations:
For rock tumbling, glass etching, or dental work, finer grades are required: Aluminum Oxide - Amazon.com where to buy aluminum oxide
Aluminum oxide is widely available from hardware stores, industrial suppliers, and specialized online retailers, with its availability largely determined by your intended use (e.g., sandblasting, polishing, or industrial applications). Depending on whether you need a small jar
: Ideal for business-grade brown aluminum oxide in specific mesh sizes (e.g., 100 mesh) for heavy-duty industrial use. or dental work
Central Pneumatic 25 lb. Black Aluminum Oxide 70-Grit Abrasive Media