About 27 years ago I thought I would melt lithium in a ceramic crucible, and then suck it up into a glass tube (using a propipet, not my mouth!), to preserve a specimen, as I had already done with sodium and potassium [incidentally the specimens prepared then are as shiny today as when prepared originally; the oxide at the open ends of the tube acts as a plug preventing further oxidation, and the tube is kept in paraffin oil anyway]. Well, the lithium ignited, I beat a hasty retreat and watched the reaction through the crack in the door, and after some kind of explosion a piece of burning lithium fell on the brand new asbestos table (yes, they were still fitting asbestos tables then), where it also exploded, leaving a hole in the surface. I subsequently explained to my colleagues that now the table really looked as if it belonged to a chemistry laboratory.

I thought then, and I see no reason to think otherwise now, that this was a simple oxidation-reduction reaction, in which the lithium "steals" the oxygen from the silicon dioxide and other oxides in the ceramic (and in the asbestos). The reaction is analogous to the well known magnesium-sand reaction, or to the formation of a black silicon mark on test-tubes in which Mg or Na has been burned (e.g. in the classic magnesium burning in steam reaction, or when I burn sodium in a flow of chlorine).