Product classification
HS code for Mullite: 2508.60
Clays (excluding expanded clays of heading no. 6806), mullite.
Classification of mullite under HS 2508.60
Mullite is classified under HS code 2508.60. This classification is found in Chapter 25, which covers salt, sulfur, earths and stone, plastering materials, lime, and cement. Heading 2508 is dedicated to various types of clays, whether or not calcined, but excluding expanded clays of heading 6806. Mullite (3Al2O3·2SiO2) is a rare silicate mineral of aluminum and silicon that is highly valued for its refractory properties, meaning it can withstand extremely high temperatures without melting or deforming. While it occurs naturally, it is often produced synthetically by heating aluminosilicates. For customs purposes, both natural and synthetic mullite are generally classified here, provided they have not been further worked into finished articles. The classification is based on the mineralogical identity of the substance as a raw material for the ceramic and refractory industries.
- Covers
- Natural mullite mineral
- Synthetic mullite (sintered or fused)
- Mullite aggregates for refractory use
- Calcined mullite-based clays
- Mullite grains and flours
- Also under 2508.60
- Imerys Refractory Minerals (fused mullite)
- Saint-Gobain ZirPro (sintered mullite)
- Almatis (tabular alumina/mullite)
- Denka
- Washington Mills.
Codes often confused with 2508.60
Common mistake. Mullite is often confused with HS code 3816.00, which covers refractory cements, mortars, and concretes. While mullite is a component of these mixtures, 3816.00 is for composite preparations, whereas 2508.60 is for the mineral itself. Another common error is 2508.30 (fire-clay), which is a different type of refractory clay. Additionally, if the mullite has been shaped into bricks or pipes, it must be classified in Chapter 69 (Ceramic products), specifically under headings like 6902 or 6903.
Top exporters and importers of HS 250860 (the code used for mullite), 2025
In 2025, the largest exporter of HS 250860 (the code used for mullite) in UN Comtrade data was China, with 31% of world exports; the largest importer in UN Comtrade data was Poland, with 21% of world imports. Countries that did not report 2025 data are estimated from partner records, which can understate them.
Figures cover everything classified under HS 250860, not only mullite.
Top exporters 2025 · share of world exports
- 1 China $20M 31% of world exports
- 2 Germany $14M 20% of world exports
- 3 Hungary $10M 16% of world exports
World total: $67M Reported figures on UN Comtrade ↗
Top importers 2025 · share of world imports
- 1 Poland $30M 21% of world imports
- 2 Germany $19M 14% of world imports
- 3 South Korea $15M 10% of world imports
World total: $143M Reported figures on UN Comtrade ↗
How these figures are built
109 countries reported 2025 trade to UN Comtrade in HS 2022, and their own totals are used. Countries that did not report are estimated from what other countries recorded trading with them. Those estimates miss trade with other non-reporting countries, so they can be low, and a non-reporting country can rank higher than shown or be missing from the list. World totals add both and leave out trade between two non-reporting countries. Figures are in current US dollars; reported imports are mostly valued CIF and exports FOB, and exports include re-exports. The UN Comtrade links show the underlying records; they can also list a few reporters left out here (regional groups and older HS editions).
Source: UN Comtrade (United Nations Statistics Division), 2025 annual data.
Brazil NCM code for mullite
Brazil classifies mullite under NCM 2508.60.00: HS 2508.60 with 00 added.
Source: Siscomex NCM table, updated Oct 2026. The Portuguese text on each NCM page is the official one.
Questions about mullite
What is the HS code for Mullite?
The HS code for Mullite is 250860 (Clays (excluding expanded clays of heading no. 6806); mullite). The HS code for mullite in its raw or aggregate form is 2508.60.
How do I classify Mullite for customs?
Mullite is classified under HS code 250860 — Clays (excluding expanded clays of heading no. 6806); mullite. This is a 6-digit subheading level code.
Is synthetic mullite classified differently than natural mullite?
Generally, no; both natural and synthetic mullite are classified under 2508.60 as long as they remain in the form of raw materials or aggregates.
Which countries are the top exporters of mullite (HS 250860)?
In 2025, the top exporters of HS 250860 (the code used for mullite) in UN Comtrade data were China ($20M, 31% of world exports), Germany ($14M) and Hungary ($10M). World exports came to about $67M, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
Which countries are the top importers of mullite (HS 250860)?
In 2025, the top importers of HS 250860 (the code used for mullite) in UN Comtrade data were Poland ($30M, 21% of world imports), Germany ($19M) and South Korea ($15M). World imports came to about $143M, adding countries' reported figures and partner-based estimates for those that did not report (UN Comtrade data). Countries that did not report 2025 data are estimated from partner records, which can understate them.
Is the HS code for Mullite the same in all countries?
The base HS code 250860 for Mullite is internationally standardized for the first 6 digits across 200+ countries. Individual countries may add additional digits for national tariff lines and specific classifications.
What is the NCM code for mullite in Brazil?
In Brazil, mullite (HS 250860) is classified under NCM 2508.60.00.