The Greenstone Leaf, a symbol of Firjak's Oakden, is a talisman that commands the respect and loyalty of all otters and squirrels. Firjack was slinging rocks at the pirates who had captured him and Bankrose and this was the last one, a green one. It was carved by the Skipper of Otters to look like a sycamore leaf. It was later given to Sunflash the Mace by Elmjak, Firjak's son. Skarlath the kestrel used the Greenstone to gather help for Sunflash.
The Greenstone appears in Outcast of Redwall.