Black chalk on paper

Black chalk on paper

Black chalk on paper

Black chalk on paper

Crayon on paper

Black chalk on paper

Crayon, and pen and pink on paper

Black chalk on paper

Crayon on paper

Crayon on paper

Black chalk on paper

Photograph: Autotype

Black chalk on paper

Black charcoal on paper

Pencil on paper

Limestone

Bronze

Calcite

Calcite, wax

Calcite, wax

Stone

Calcerous stone

Plaster, paint

Plaster, stone, paint