Which crucible material can withstand the highest temperature?

Calcia-stabilized zirconia crucibles are rated up to 2300°C in inert or reducing atmospheres, higher than magnesia (2200°C) and alumina (1600°C). For most general laboratory work, alumina is sufficient and the most economical.

What is the difference between alumina and zirconia crucibles?

Alumina (Al₂O₃) is a lower-cost, general-purpose ceramic rated up to 1600°C and is the standard for sintering, ashing and TGA/DSC. Zirconia (ZrO₂) withstands higher temperatures up to 2300°C, resists wetting by molten precious metals and is preferred for melting platinum, gold and reactive alloys.

Which crucible is best for alkaline melts?

Magnesia (MgO) is the best choice for strongly alkaline and alkaline-earth melts because it resists attack by basic slags and fluxes. Alumina reacts with strong alkalis, so MgO or zirconia is preferred for reactive or basic melts.

Material Guide

Alumina vs Zirconia vs Magnesia Crucibles

Which ceramic crucible material fits your process? A factory-level comparison of the three most common oxide crucibles — temperature limits, chemical resistance, cost and where each one shines.

Alumina (Al₂O₃), magnesia (MgO) and zirconia (ZrO₂) are the three workhorse oxide ceramics for laboratory and industrial crucibles. They share high refractoriness, but differ sharply in maximum temperature, chemical resistance and cost. Choosing the wrong one either wastes budget or — worse — contaminates your melt or cracks mid-run.

1. Comparison at a Glance

Property	Alumina (Al₂O₃)	Magnesia (MgO)	Zirconia (ZrO₂)
Max service temperature	Up to 1600°C	Up to 2200°C	Up to 2300°C (inert/reducing)
Typical purity	99% (95–99.7% available)	99%	Calcia-stabilized
Best for alkaline melts	Poor — reacts with strong alkalis	Excellent	Good (resist wetting by metals)
Thermal-shock resistance	Moderate	Lower — heat slowly	Good (best of the three)
Relative cost	Lowest	Higher	Highest

2. Alumina (Al₂O₃) — the General-Purpose Workhorse

Alumina is the most widely used crucible ceramic because it is cost-effective and chemically stable across a broad range of neutral, oxidizing and acid environments. With a long-term service temperature up to 1600°C, it covers the majority of everyday high-temperature work: ceramic sintering, ash determination, metal melting and thermal analysis (TGA/DSC).

Choose alumina when your process stays below 1600°C and does not involve strongly alkaline or fluoride fluxes.
Avoid alumina with molten alkali carbonates, strong alkaline melts and fluoride fluxes — these attack the ceramic.

Browse alumina (Al₂O₃) crucibles →

3. Magnesia (MgO) — for Alkaline & Reactive Melts

Magnesia crucibles are the go-to when you are melting strongly alkaline or alkaline-earth materials, refining non-ferrous metals, or working with slags and fluxes that would attack alumina. Rated up to 2200°C, magnesia resists basic melts that destroy other oxides. Its trade-offs are lower thermal-shock resistance (heat it gradually) and a higher price.

Choose magnesia when your melt is basic or highly reactive and temperatures may approach 2000°C+.
Handle with care — magnesia is sensitive to rapid temperature change; ramp slowly.

Browse magnesia (MgO) crucibles →

4. Zirconia (ZrO₂) — for Precious Metals & Ultra-High Temperatures

Calcia-stabilized zirconia crucibles are engineered for the most demanding work: melting precious metals (platinum, gold, palladium, silver), specialty alloying and crystal growth. Zirconia resists wetting by molten metals, offers the best thermal-shock resistance of the three, and is rated up to 2300°C in inert or reducing atmospheres. It is also the most expensive option.

Choose zirconia when you need maximum refractoriness or are melting precious / reactive metals.
Note — oxidizing service lowers the effective temperature limit; confirm your process conditions with our team.

Browse zirconia (ZrO₂) crucibles →

5. How to Decide

Below 1600°C, non-alkaline → alumina (best value).
Alkaline or reactive melt → magnesia.
Precious-metal melting or 2000°C+ → zirconia.
Always confirm atmosphere, heating rate and melt chemistry — they shift the practical temperature limit.

Not sure which material fits your melt? Tell us your temperature, atmosphere and sample chemistry — our engineers will recommend the right crucible or quote a custom size within 24 hours. Contact Scuvette →