Montblanc Writers Edition Mark Twain Fountain Pen. Limited Edition of 15,000 pens produced. Medium Nib. Piston operated fountain pen. Rhodium-plated 18 karat gold nib with engraving representing nautical units used for navigating the Mississippi River in his famous work, "The Adventures of Tom Sawyer and Huckleberry Finn." The dark blue resin cap and barrel, with its engraved design, are reminiscent of the waves of the Mississippi River. The cap features Twain's engraved signature.