Aluminum Oxide - 90 - Micron Tan 1lb by Danville SKU 984-0544AA 123 $25.99 1 2 3 4 5 6 7 8 9 10+ Quantity Quantity Add to cart 90 Micron Aluminum Oxide Medical Grade Alpha Alumina 1 Lb. Tan, will not discolor enamel or composite surfaces, for use with Microetcher.