"You crushed 19 Mortar Barnacles (+23 iMG, -57 energy). 19 Barnacle Talc were created, but destroyed, because you couldn't carry them."
I'm not sure if this is intended behaviour or a bug, but talc grinding behaves like element grinding, what you cannot carry is simply lost, instead of dropped to the ground. While this makes sense for elements, since they can only be carried in elemental bags, talc can be dropped on the ground and picked up again. If it is intended behaviour, then let this serve to warn others so that they may learn from my mistake. :)
(This happened because I was grinding barnacles at the same time I was incubating animals; seven caterpillars arrived while I was grinding.)