We Dance With The Fella That Brung Us

[sissydear]

The mica he uses is not crystalline, more of a powdery substance and yes it does melt.

[lstmmrbls]

http://www.dumico.com/what-is-mica/

http://digitalfire.com/4sight/material/mica_1018.html?logout=yes

I wonder if the powder is synthetic Mica?

[richsantaclaus]

Mica

Alternate Names: Isinglass, Muscovite, Biotite, Phlogopite

Oxide Analysis Formula K2O 11.80% 1.00 Al2O3 38.40% 3.01 SiO2 45.30% 6.02 LOI 4.50 Oxide Weight 762.38 Formula Weight 798.31 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.

Stable, virtually inert except to hydroflouric and concentrated sulfuric acid. Impervious to water and atmosphere. Unaffected by exposure to UV light, water or extended low and high temperatures (up to 1800C). Free of asbestos and other non-asbestos fibrous materials. It is non-flammable, non-toxic and non-hazardous. Mica is invaluable in the electrical and electronics industries because of its unique combination of physical, chemical and thermal properties, low power loss factor, dielectric constant and dielectric strength. Also used in insulation, paint, metalurgical, and polymers.

Mica is used in low fire clay bodies to add a sparkle effect. Since it melts just below 2000F its use for this purpose is limited to below cone 02. Water washed micas are superior for this purpose. While this technique has been employed by various potters it is actually an old process. For more information about its history, see the book "All That Glitters" (available at www.axner.com).

Data sheets for various mica products quote a wide range of decomposition and melting temperatures (as high as 1800C for melting and 1500C for decomposition). A typical melting point of muscovite is around 1250-1300C. However there are many different kinds of mica. Thus it is impossible to give a formula and difficult to give a general chemistry (micas are never employed in ceramics for their chemistry anyway, the mineralogy of the material is what is important).

[Killermarbles]

Ttt