instrumentation (a piece of equipment or tool) used to effect an end

a piece of calcite or a similar substance, usually in the shape of a crayon, that is used to write or draw on blackboards or other flat surfaces

a stick of black carbon material used for drawing

writing implement consisting of a colored stick of composition wax used for writing and drawing

a writing implement with a small toothed wheel that cuts small holes in a stencil

a writing implement for making a mark