Shagreen

1680: "This small book with its matching gold stylus would have fitted into a pocket. It might have been used as a diary or a notebook. The cover is of black shagreen, a type of leather made from shark or fish skin, and decorated with round-headed gold studs. The inside cover is lined with a thick paper painted with leaves in gold on a purple ground. When the book is closed, four bands of engraved gold form a tube into which the stylus fits. The book would originally have held paper, which would have been coated so that the metal stylus would leave a track like that of a pencil on paper." Link