Formula: Li2O.Al2O3.4SiO2 or LiAl(Si2O6)
|DENS – Density (Specific Gravity)||2.60|
|MLPT – Melting Point (MP)||1421C M|
The name is from the Greek spodos, meaning burnt to ash. Spodumene is a silicate mineral often referred to as lithium feldspar. Its mineral form is characterized by hard needle-like grains of brilliant white color. It is used in ceramics as a source of lithia.
Lithia is a very powerful flux, especially when used in conjunction with potash and soda feldspars. As one of only a few natural lithium source materials, spodumene is a valuable component in glass and ceramic/enamel glazes (Li2O reduces thermal expansion, melting temperature and viscosity of the glaze melt).
Spodumene is only slightly soluble (in contrast to lithium carbonate). Because spodumene is a natural combination of silica, alumina and lithia it melts better than a chemically equivalent mixture of lithium carbonate, kaolin and silica. Since almost all raw glazes contain kaolin and silica it is normally fairly easy to juggle recipe ingredients in a ceramic chemistry calculation program to introduce spodumene to replace lithium carbonate.
Some types of spodumene do contribute to the formation of bubbles in the glaze slurry. Spodumene is a little more readily fusible than petalite since it is higher in lithium.
Article from http://digitalfire.com