2528.00.00.10 - Natural calcium borates

This HTS category, 2528.00.00.10, specifically covers natural borates that are primarily composed of calcium, along with their concentrated forms. These materials are sourced directly from natural deposits and have not undergone processes that would separate them from natural brines. The classification includes these natural calcium borates whether they have been calcined (heated to remove water or other volatile substances) or not. This ensures that products derived from naturally occurring calcium borate deposits, in their raw or processed (but not chemically separated) states, are correctly identified.

It is crucial to distinguish this category from its sibling, 2528.00.00.05, which covers natural sodium borates. While both fall under the broader heading of natural borates, the key differentiator here is the primary cation. This sub-classification focuses solely on borates where calcium is the predominant mineral component, as opposed to sodium. Furthermore, it excludes borates that have been chemically separated from natural brines, which would be classified elsewhere.

As this is a leaf node within the HTS, there are no further subcategories under 2528.00.00.10. Classification at this level is definitive for natural calcium borates and their concentrates, provided they meet the criteria of being derived from natural deposits and not separated from brines. Examples of products falling under this code include naturally occurring calcium borate minerals like colemanite or ulexite in their crude, crushed, or concentrated forms, suitable for industrial use.