Pierre aiguiser La Lune unlabelled (120 x 60 x 23mm)

Size: 120 x 60 x 23mm weight: 439gr.
Density: xxgr./cm³ / Estimated grit size: ultra fine > 12k
Usage: with water, glycerine or oil
FGBC wrote in their Instructions to use the stone with oil
Color: dark-purple, violet with a visible flash like pattern
Supplier/Distributor:
F.G.B.C. / F. Ghelfi, Birroleau & Cie. 
this stone is un-labelled

Pierre aiguiser La Lune un-labelled (160 x 75 x 30mm)

Size: 160 x 75 x 30mm weight: 1180gr.
Density: xxgr./cm³ / Estimated grit size: ultra fine > 12k
Usage: with water, glycerine or oil
FGBC wrote in their Instructions to use the stone with oil
Color: dark-purple, violet with a visible flash like pattern
Supplier/Distributor:
F.G.B.C. / F. Ghelfi, Birroleau & Cie. or Manufrance
this stone is un-labelled

Pierre La Lune small 90 x 32 x 19mm (F.G.B.C.)

Size: 90 x 32 x 19 mm weight:  158gr.
Density: XXXgr./cm³ /  Estimated grit size:  very fine > 15K
Usage: with water, oil or glycerin
(FGBC says to use the stone with oil)
Color: red-purple slate with metallic sparkle look
Supplier/Distributor: F.G.B.C. (F. Ghelfi, Birolleau & Cie.), Manufrance