Add spodumene to this floating blue: To moderate the excessive variegation

Tuesday 23rd July 2013

GA6-C (left) and GA6-E (right) at cone 6 oxidation. GA6-E adds 4% insight-live.com/material/1287">spodumene to GA6-C, which contains 4% rutile (the base is 80% Alberta Slip and 20% Frit 3134). Notice how the spodumene suppresses the large pale, overly variegated areas that commonly develop in GA6-C, producing a more uniform blue.

Why? The small spodumene addition introduces Li2O along with Al2O3 and SiO2, changing the melt chemistry and therefore the crystallization and phase-development behavior of the rutile/iron-bearing glaze during cooling. Thus it is safer to regard spodumene as modifying the titanium-related crystallization rather than simply reducing it. Like GA6-C, GA6-E requires a slow-cool firing schedule to develop the rich blue (e.g. C6DHSC). Both look best on darker-burning bodies.

Pages that reference this post in the Digitalfire Reference Library:

Spodumene, GA6-C - Alberta Slip Floating Blue Cone 6, Rutile Blue Glazes, FLB - Floating Blue

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.