In addition to admiring many beautiful baskets in the Doris Borhauer Basket Collection in Sitka, Alaska I learned about Baleen Basketry.
Baleen or "whale bone" is the tough keratin that comes from the mouth of plankton eating whales. Inupiaq native artisans adapted the traditional coiled willow-root basket style to form baleen baskets beginning in the early 1900's. Artisans continue to create coiled baskets with this material. Most black baleen baskets I saw in Alaska had a ivory circle base and a carved ivory decorative top to the lid. They were beautiful and skillfully made!