The Sea-Kings perfected a way of creating “green steel” – a metal that is tinged green. The Gwinnish lost this ability until around CY 8800 when a contained vat of the algae that was used was discovered (many rumors abound regarding its location). Now, there is a single forge center in a secret location that fosters the algae colony. It is also rumored to be quenched in high concentrate salt water that the algae lives in. Those not a follower of Elancil wielding items of this type cause them to become brittle and crack within a month. Almost off of Gwinn’s Elite marines have their signature sea-axes made from this material.
d20 [specific] Requirements:
It has immunity to rust – it won’t corrode; while being forged, it is much easier to add extra Resilience – half the normal cost.