Caprock Native Sulfur
Native sulfur from limestone caprock formations above salt domes, mined via conventional methods. Under HTS 2503.00.00.90 as other non-sublimed, non-precipitated sulfur.
Import Duty Rates by Country of Origin
Alternative Classifications
This product could be classified differently depending on its characteristics or intended use.
If heavily contaminated with calcium sulfate
Gypsum-rich mixtures classify as natural salts of Chapter 25 heading 2501.
If iron content exceeds 70% as Fe2O3 earth colors
Chapter exclusion (b) directs high-iron earth colors to 2821.
Not sure which classification is right?
The Tariff Assistant works through the GRI rules on your specific product to reach the right HTS code — and can price the duty on it in the same conversation.
Import Tips & Compliance
• Include stratigraphic reports proving caprock origin versus synthetic
• Avoid oversized blocks over 50kg that resemble cast precipitated sulfur
• Test for limestone impurities exceeding 5% to prevent 2530 reclassification
Related Products under HTS 2503.00.00.90
Crude Native Sulfur Ore
Raw sulfur extracted from natural volcanic deposits or caprock formations, containing impurities like dirt and moisture. Classified under HTS 2503.00.00.90 as unrefined sulfur of natural origin, excluding sublimed, precipitated, or colloidal forms per Chapter 25 exclusions.
Recovered Frasch Process Sulfur
Yellow solid sulfur blocks recovered via the Frasch hot-water mining method from underground Gulf Coast salt domes. Falls under HTS 2503.00.00.90 as crude sulfur not further refined, distinct from precipitated forms.
Volcanic Sulfur Crystals
Bright yellow crystalline sulfur formed around fumaroles in active volcanoes like those in Indonesia or Japan. HTS 2503.00.00.90 covers this natural sulfur variety excluding sublimed or colloidal processing.
Bulk Lump Sulfur from Mines
Irregular lumps of native sulfur mined from surface outcrops, typically 99% pure with rock inclusions. Classified in HTS 2503.00.00.90 as other crude sulfur not meeting sublimed or precipitated definitions.
Natural Sulfur Pebbles
Small, rounded natural sulfur pebbles collected from sedimentary deposits, suitable for industrial grinding. HTS 2503.00.00.90 includes these unprocessed forms excluding chapter exclusions.
Polish Native Sulfur Lumps
Native sulfur lumps from Polish Carpathian deposits, valued for low impurity profile in fertilizer production. HTS 2503.00.00.90 covers this European crude sulfur source.