2818.10.20.10 - White, pink or ruby, containing more than 97.5 percent by weight of aluminum oxide

This HTS category, 2818.10.20.10, specifically covers artificial corundum in grains, ground, pulverized, or refined form, which contains a high purity of aluminum oxide, exceeding 97.5 percent by weight. This material, also known as alumina, is produced synthetically and is characterized by its hardness, durability, and inertness. Its precise chemical composition, particularly the high aluminum oxide content, is a key defining factor for classification within this heading.

Distinguishing this subcategory from its sibling, 2818.10.20.90 ("Other"), is critical. While both fall under refined artificial corundum, this specific classification is reserved for those products where the aluminum oxide content is demonstrably above the 97.5% threshold. The "Other" category would encompass refined artificial corundum that does not meet this high purity standard or exhibits other properties not covered by the specific 97.5% criteria. The physical state—grains, ground, pulverized, or refined—is common to both siblings, with the chemical composition being the differentiating factor.

As this is a leaf node in the HTS, there are no further subcategories to introduce. Therefore, classification at this level relies entirely on meeting the specified criteria of form (grains, ground, pulverized, or refined) and the high aluminum oxide content of over 97.5 percent by weight. Examples of goods that would fall here include highly purified, finely ground alumina powders used in advanced ceramics, abrasives, and refractories, where the superior purity dictates their application and value.