Digitalfire Ceramic Materials Database

Logged in as Level 2 access: Logout

You should always be testing. But it is wasted without an audit trail. Document your lifetime of recipes, firing schedules, test results, pictures and much more in a private account at It is the future, the next step after desktop Digitalfire Insight.

Watch the video, learn more or sign-up at

Strontium Carbonate

Formula: SrCO3 or SrO.CO2
Alternate Names: Strontianite

Oxide Weight103.60
Formula Weight147.58
Enter the formula and formula weight directly into the Insight MDT dialog (since it records materials as formulas).
Enter the analysis into an Insight recipe and enter the LOI using Override Calculated LOI (in the Calc menu). It will calculate the formula.
DENS - Density (Specific Gravity) 3.6
HMOH - Hardness (Moh) 3.6
GSPT - Softening Point 723C D
BDLB - Bulk Density lbs/cu. ft. (Packed) 105

Strontium Carbonate is a slightly soluble source of SrO used in glazes.

There is disagreement about when it decomposes (data sheets vary from 1075-1100C, one even indicates 1340C) as follows:

SrCO3 -> SrO + CO2

The 'Ceramic Industry Materials Handbook' states that it starts to disassociate as early as 800C in a purely oxidizing atmosphere, whereas a CO2 atmosphere might delay break-down until around 1220C. This information is supported by the fact that when the more stable calcium and barium carbonate are added to bodies, pinholing and blistering are greater than bodies containing strontium. Wikipedia says it melts and decomposes at the same time, 1100C.

Strontium carbonate is often recommended as a substitute for barium to produce matte glazes. Use about 75% as much and test first to make sure color response is the same. However strontium is not a substitute for barium as a precipitator of soluble salts in clay bodies because it combines with SO4-- ions in the water to form a compound that is not nearly as insoluble as BaSO4.

Viscous zirconium silicate glazes can be smoothed with the addition of strontium carbonate.

Strontium is considered a safe material. Some people confuse SrO with Strontium 90, an isotope released from atomic reactions; they are not the same thing.

Strontium carbonate produces gases as it decomposes and these can cause pinholes or blisters in glazes. There are many strontium frits available and incorporating one of them to source the SrO instead of raw strontium carbonate is a classic application of ceramic chemistry calculations. The resultant glaze will be more fusible and will have better clarity and fewer defects. Strontium frits have become much more common of late and are useful to producing brilliant transparent glazes without having a high expansion (like those based on Na2O and K2O). Please read the information about the oxide SrO to fully appreciate the value of SrO frits, not just as alternatives to this material, but as excellent ways to produce brilliant glazes.


Strontium carbonate self destructing

Strontium carbonate fired at 1800F and then allowed to rehydrate in the air for two days. It is crumbling like this all by itself, similar to what calcium carbonate does as it rehdrates.

Cone 6 porcelain marbled and thrown

These bowls are made from a mixture of white and stained New-Zealand-kaolin-based porcelain (Plainsman Polar Ice) fired at cone 6. The body is not only white, but very translucent.The clear glaze is G2916F clear, it uses a Fusion strontium frit.

LOI profiles of more common glaze and body materials

These are pure samples (with 2% binder added) of (top left to bottom right) strontium carbonate, nepheline syenite, cobalt carbonate, manganese dioxide, bentonite (in bowl), 6 Tile kaolin, New Zealand kaolin and copper carbonate. I am firing them at 50F increments from 1500F and weighing to calculate loss on ignition for each. I want to find out at what temperature they are gassing (and potentially bubble-disrupting the glaze they are in or under). Notice how the copper is fuming and spitting black specks on the shelf, this happens right around 1500F. These stains on the shelf darkened considerably when the kiln was fired higher.

Out Bound Links

In Bound Links

By Tony Hansen

XML for Import into INSIGHT

<?xml version="1.0" encoding="UTF-8"?> <material name="Strontium Carbonate" descrip="" searchkey="Strontianite" loi="0.00" casnumber="1633-05-2"> <oxides> <oxide symbol="SrO" name="Strontium Oxide, Strontia" status="U" percent="70.200" tolerance=""/> </oxides> <volatiles> <volatile symbol="CO2" name="Carbon Dioxide" percent="29.800" tolerance=""/> </volatiles> </material>

Feedback, Suggestions

Your email address


Your Name


Copyright 2003, 2008, All Rights Reserved
Get a free INSIGHT software trial

INSIGHT is ceramic chemistry
calculation software that runs on
Windows, Mac and Linux and talks
to this web site. ()