Lode deposits consist of ore minerals in veins or disseminated in rock. These deposits require blasting, milling, or leaching to recover the gold. When a lode deposit weathers, gold and other minerals that resist weathering remain. Some of these minerals are called 'heavy minerals' because a given volume weighs more than the same volume of most other minerals.
Many heavy minerals are black and make up what are commonly referred to as 'black sands'.
Gold in the sand and gravel in the streambed can be recovered by panning. The state's streams that contain placer gold are also important for the plant and animal communities they support. You must have a formal HPA for sluicing and dredging. The booklet also lists the classes of different streams and seasonal restrictions to certain activities on the various streams. It is important to know where in Washington you can go to find land that is 'open' for recreational panning.