well mold + clay definitely equates to pottery.. unfortunately you probably need to make the other combine first due to the flagging?
so the question becomes, do you have to combine other items with the clay, or is it one seperate combine to make the totem then a second for clay + mold.
trying each combination of ingredients at random is not going to get anywhere unless we get very lucky, so from the text..
"You will need to take the clay, the medallion, wood I gave you, and the essence and learn which to craft together."
I'd try every combination of those 4 in each tradeskill container (5 if there are two different medallions? and have some of the "secondary" ones been tried, like mixing bowl or mortar and pestle, or any of the Planar kits?)
With 4 items, there's 11 combinations to try:
1 combo of all 4
4 combos of 3 items
6 combos of 2 items
If we need to get into the tradeskill tools, then there are soooo many combinations I don't want to think about it.