Goldie's being pretty cool, but Kurt is so mercurial.

Her mood was so mercurial that she drew, time and again, the eyes of all at the table.

If only this strange creature were not so mercurial...

I tried to picture Züpfner: his brown hair, fair skin, straight build, a kind of Alcibiades of German Catholicism, only not so mercurial.

He was not so mercurial and impetuous as the others had believed him to be, but was capable of a steady and undemonstrative devotion.

Furneaux was never so mercurial, never so ready to jump from one subject to another, as when his subtle brain was working at high pressure.

So capricious, so ephemeral, so mutable, so mercurial, so impermanent are the whims of humanity, and so unstable its idolatries and adorations.