Crucible Micro, Porcelain

Quick Answer: A micro porcelain crucible is a very small glazed porcelain crucible used to heat, ignite, ash or melt samples of only a few milligrams, where a standard crucible would be too heavy for small changes in mass to be weighed accurately.

Why Micro Size Matters

In gravimetric work, what is measured is a change in mass. If a sample weighs a few milligrams and the crucible many grams, small errors in weighing the vessel can swamp the result. A micro crucible keeps the vessel mass low, so the balance works nearer to the sample mass and the change is easier to measure. Small crucibles also heat up and cool down faster, which shortens each heating and weighing cycle.

Micro crucibles are used in microanalysis, for ashing small tissue or food samples, igniting small precipitates, and in micro-scale teaching practicals that save reagents by working with tiny quantities. They are heated on a small pipeclay triangle over a micro burner or Bunsen, or placed in a muffle furnace.

Being small, a micro crucible is easily knocked over and awkward to grip. Handle it with fine-tipped tongs or forceps, and cool it in a desiccator before weighing. Capacity, and whether a lid is included, are not stated in the listing; for larger samples see the squat form porcelain crucible.

Specifications

Applications

• Microanalytical ignitions and ashing of very small samples.
• Micro-scale chemistry practicals that save reagents and cut waste.
• Melting tiny amounts of low-melting solids for observation.
• Igniting small precipitates in semi-micro analysis.

Care & Handling

• Heat and cool gradually; even small crucibles crack under sudden temperature change.
• Handle only with clean tongs, since fingerprints add measurable mass.
• Number each crucible with a heat-stable marking before its first ignition.
• Store micro crucibles in a desiccator or covered box so they stay clean and dry.

Why Choose LabEquip

Microanalysis labs, pharmaceutical research groups and colleges running micro-scale practicals buy micro crucibles in sets. LabEquip lists them in General Lab Products; ask about lids and quantities through the contact page.

Frequently Asked Questions

When should a micro crucible be used instead of a standard one?

When the sample is only a few milligrams. A lighter crucible makes small mass changes easier to measure accurately, and it heats and cools more quickly.

Can a micro porcelain crucible go in a muffle furnace?

Yes, glazed porcelain crucibles are commonly ignited in muffle furnaces. Put them in while the furnace is cool or warm, and let them cool gradually before moving them to a desiccator.

How do I hold such a small crucible?

Use fine-tipped crucible tongs or flat forceps rather than full-size tongs, and grip it at the rim. Never use fingers, which leave grease and moisture.

Why must the crucible be heated to constant mass first?

New or washed crucibles hold traces of moisture and volatile matter. Heating, cooling in a desiccator and weighing until two readings agree gives a reliable empty mass to subtract later.

What heat source suits a micro crucible?

A micro burner or a small Bunsen flame on a small pipeclay triangle, or a muffle furnace. A large, roaring flame is hard to control around such a small vessel and can overheat the contents.

Which chemicals can damage porcelain crucibles?

Hydrofluoric acid and hot concentrated alkalis attack the glaze, and fusions with alkali carbonates or hydroxides corrode porcelain. For those, crucibles of nickel, zirconium or platinum are used.

Last Updated: September 2026