Coticule standard

Coticule sharpening stones come in 2 layers. The top layer is 5 to 10 mm thick, depending on the vein (Coticule veins are not all the same thickness in the quarry). This layer of Coticule is glued to a black shale base (unusable), because Coticule is a relatively fragile material. Tiny cracks can be seen on the sides of the stone. This is absolutely normal for this type of material and in no way affects its sharpening properties.

Coticule sharpening:
This is always done with water. Simply moisten the surface of the Coticule: the stone must not be immersed. During sharpening, the surface of the Coticule releases garnets. The more garnets it releases, the more abrasive the paste.
A method commonly used to increase abrasiveness (at the start of sharpening) is to make a garnet-rich sharpening paste on the surface of the Coticule using a second small Coticule: to do this, one side of the small Coticule is rubbed against the Coticule side of the sharpening stone. The creamy white sharpening paste quickly forms.
To progress with the sharpening, simply rinse this paste with water to obtain a just damp stone.

Advice:
Coticule is a non-porous stone, so it cannot become clogged.
Only use water and not oil when sharpening. Oil should only be applied to porous stones to prevent iron particles from depositing in the pores.
Longevity of the stone: the longevity of the stone depends on how it is used. The more intense the use, the quicker the stone will wear out. Generally speaking, stones last 20 years with normal use.