Crude natural garnet in irregular pieces or as mined falls within this heading (27722). Once garnet is crushed, sized, and graded specifically for abrasive use — particularly when sold in standardized mesh sizes for waterjet or blasting applications — it may be classified under headings for prepared abrasives. The degree of processing and the form in which the material is presented at import are the key classification factors; consult a licensed customs broker for borderline cases.

At the crude stage covered by this heading, pumice is classified by its natural, unprocessed form regardless of intended end use. Crushed pumice (bimskies) for lightweight concrete aggregate, raw pumice blocks for abrasive use, and bulk pumice for horticultural soil amendment all fall here. Pumice that has been further processed — shaped into personal care bars, blended into cosmetic formulations, or packaged as a finished product — would be classified under different headings reflecting the finished-goods nature of the item.