Lithium carbonate is now incredibly expensive. The glaze on the left employs it. But I was able to source the Li2O from spodumene instead. Spodumene has a complex chemistry, but the oxides that it contains (other than Li2O) are those common to glazes anyway. Using my account at insight-live.com, I did the calculations and got a pretty good match in the formulas (lower section in the green boxes). Then I made 10 gram balls and did a melt flow test at 2200F (notice the long crystals in the pools of glass below the runways). And I glazed buff stoneware test (below the flow tests). Not surprisingly, this glaze is very runny. That's why the tiny yellow crystals grow during cooling, they produce the gold effect this recipe is known for. The spodumene version is very similar, perhaps better. Notice my calculated cost: $15.47/kg vs. $8.12/kg.