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Magris Jetfil H 290 Talc

Oxide Analysis Formula
SiO2 49.40% 1.02
Al2O3 7.60% 0.09
MgO 32.40% 0.99
CaO 0.30% 0.01
Fe2O3 1.60% 0.01
LOI 11.00%n/a
Oxide Weight 112.81
Formula Weight 126.75


2022: Claimed to be a substitute for Texas talc. However its chemistry is quite different. It only has ~2% less MgO but the CaO is 3.5 (vs 0.3), Al2O3 is 7.6 (vs 0.5) and SiO2 is 49.4 (vs 53.5). But the biggest difference is the amount of Fe2O3, 1.6% vs <0.5.

If you are using this as a substitute for Texas talc in slip casting bodies it will likely be necessary to adjust the amount of deflocculant and water. You will likely have to read up on deflocculation and be willing to measure specific gravity and make test batches to fine tune a workable recipe. If ware does not have the plastic strength formerly, consider upping the percentage or ball clay (at the cost of non-talc ingredients) or using a more plastic (finer particled) ball clay.

Related Information


Magris Talc home page
Magris Jetwhite Talc 2H data sheet
Materials Natural Talc C-98
Materials Talc
A source of MgO for ceramic glazes, a flux or thermal expansion additive in clay bodies, also used in the manufacture of cordierite.
By Tony Hansen
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