Texas talc (left) and Montana talc (right)

Wednesday 24th October 2012

Texas insight-live.com/material/1620">talc contains some amorphous carbon. The carbon is not stand-alone, but as CO2 in the dolomitic part of the ore. It produces ~7% LOI between 750-850C. Even though the powder color is so much darker in the raw form, it fires whiter! But there is more going on here. On paper, both contain about 0.5% Fe2O3. But the iron species in the two talcs are different. In Texas talcs, the iron is part of the crystal lattice. But, in the Montana material, that 0.5% Fe2O3 is an external iron oxide mineral species, a physical contaminant. While the Montana material fires much darker because of this that iron seems to have little affect on the color of the raw white powder.

Pages that reference this post in the Digitalfire Reference Library:

Amtalc-C98, Pioneer 2661 Talc, Silverline 303 Talc, Talc, Natural Talc C-98

This post is one of thousands found in the Digitalfire Reference Database. Most are part of a timeline maintained by Tony Hansen. You can search that timeline on the home page of digitalfire.com.