Critical Minerals in Glass and Ceramics
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Glass and ceramics use several minerals as fluxes, colourants and refractories, and two of them are on the EU critical raw materials list because of supply concentration: feldspar and boron. Feldspar and nepheline syenite take 53% ceramics and 47% glass in the United States, glass and ceramics are the leading domestic users of boron, and selenium goes 20% into glass worldwide. Türkiye supplied 99% of the EU's boron and, after its exports doubled, 51% of the EU's feldspar needs in the 2023 assessment.
47% / 53%
U.S. feldspar use in glass manufacturing and in ceramics, pottery and other uses
20%
of world selenium use in 2025 was glass manufacturing (decolourising container glass)
4%
of world lithium use in 2025 was ceramics and glass
99%
of EU boron sourcing came from Türkiye in the EU's 2023 assessment
Which critical minerals do glass and ceramics use?
The table lists the uses USGS documents for glass and ceramics, with the supply fact most relevant to each mineral.
| Mineral | Use in glass or ceramics | Supply and substitutes |
|---|---|---|
| Feldspar and nepheline syenite | Flux in glass and pottery: 53% ceramics, pottery and miscellaneous, 47% glass including fiberglass insulation, flat glass, containers and specialty glass (U.S.). | World output about 31 million tonnes in 2025, led by India (6.0 million), Türkiye (5.3), Iran (3.9) and China (3.7). Nepheline syenite is the major alternative; clays, slag, talc and spodumene can replace feldspar in some uses. EU critical raw material since 2023. |
| Boron | Glass and ceramics are the leading U.S. users of boron products; ulexite is a primary ingredient of specialty glasses and ceramics. | Türkiye produced 1.5 million tonnes of refined borates in 2025, Chile 300,000 and Bolivia 380,000 tonnes of ulexite (USGS does not give a world total). EU critical raw material; metallurgy-grade boron is strategic. Phosphates can replace borates in some enamels. |
| Lithium | Lithium minerals are used directly as concentrates in ceramics and glass: 4% of world use. | Sodic and potassic fluxes can replace lithium in ceramics and glass (USGS). |
| Zirconium (zircon) | Ceramics are the leading end use of zircon; other uses are foundry sand, refractories and zirconium chemicals. | Mine output about 1 million tonnes in 2025, down 12%. Chromite and olivine can replace zircon in some foundry uses. |
| Selenium | Decolourises the green tint iron impurities give container and soda-lime glass: 20% of world use. | A byproduct of copper refining. Metallurgy takes 40%. |
| Rare earths | Ceramics and glass, and polishing, are named among end uses. | Magnets are the leading global use; USGS gives no ceramic or glass share. |
| Tellurium | Pigments that produce colours in glass and ceramics. | Solar cells take 70% of world use. |
Source: USGS Mineral Commodity Summaries 2026 chapters on feldspar, boron, lithium, zirconium and hafnium, selenium, rare earths and tellurium; EU status from the EU 2023 study.
Why are feldspar and boron on the EU list?
Both are on the EU list because the EU depends on a single supplier. The EU's 2023 assessment made feldspar critical because import dependency rose and imports from Türkiye doubled to supply 51% of EU needs, and the study lists Türkiye as the largest global supplier of boron (48%) and the source of 99% of EU boron sourcing. Boron appears twice in Regulation (EU) 2024/1252: on the critical list, and, in its metallurgy grade, on the strategic list. Feldspar is on none of the other three lists, and boron is also on the U.S. list since 2025.
Frequently asked questions
Is feldspar a critical mineral?
Feldspar is a critical raw material in the EU, added in the 2023 assessment because EU imports from Türkiye doubled to supply 51% of EU needs. It is not on the U.S., Australian or Canadian lists.
What is boron used for in glass?
Boron is used in glass and ceramics, which are the leading domestic users of boron products in the United States. Ulexite is a primary ingredient of specialty glasses and ceramics, and USGS says phosphates can replace borates in some enamels.
How much lithium goes into glass and ceramics?
About 4% of world lithium use in 2025, according to USGS, with batteries taking 88%. Lithium minerals are used directly as concentrates in glass and ceramics, and sodic and potassic fluxes can replace them.
Which critical mineral is used to decolourise glass?
Selenium. It decolourises the green tint that iron impurities give container and other soda-lime silica glass, and glass manufacturing took about 20% of world selenium use in 2025.
Sources
Read on October 13, 2026. Figures on this page come from these documents; where a number is an estimate, the source says so.
- USGS Mineral Commodity Summaries 2026: feldspar and nepheline syenite
- USGS Mineral Commodity Summaries 2026: boron
- USGS Mineral Commodity Summaries 2026: lithium, selenium, tellurium and zirconium and hafnium. Other chapters at mcs2026-selenium.pdf, mcs2026-tellurium.pdf and mcs2026-zirconium-hafnium.pdf
- USGS Mineral Commodity Summaries 2026: rare earths
- European Commission: Study on the Critical Raw Materials for the EU 2023. Executive summary and Tables A and B
