Stone Treasures
One of the treasures found on Oregon beaches is agates. These stones are found in gravel deposits in beach cliffs and are deposited on the beaches each winter as the bluffs erode. Formed through heat and pressure, agates take on many different colors and patterns. They can be clear to orange to blue-gray in color and often have a milky exterior. They are dense and hard enough that they polish into gleaming stones that are popular with rock hounds. The best time and places to collect agates are winter beaches with gravel beds exposed by storms and waves.
Source: Flotsam, Jetsam and Wrack.