Incomprehensible; fathomless; inscrutable.
Opaque; obscure; not translucent or transparent.
Not penetrable.
A person not openly given to friendship.
Unpredictable, erratic or fickle; mercurial.
The metal mercury.
An amalgam of mercury and tin applied to the backs of mirrors, quicksilvering.
To overlay with quicksilver.
To treat with quicksilver.