The icon, traditionally half-length when in a semi-dome, which became adopted for panel icons also, depicts Christ fully frontal with a somewhat melancholy and stern aspect, with the right hand raised in blessing or, in the early encaustic panel at Saint Catherine's Monastery, the conventional rhetorical gesture that represents teaching. The left hand holds a closed book with a richly decorated cover featuring the Cross, representing the Gospels. An icon where Christ has an open book is called "Christ the Teacher", a variant of the Pantocrator. Christ is bearded, his brown hair centrally parted, and his head is surrounded by a halo. The icon usually has a gold ground comparable to the gilded grounds of Byzantine mosaics.