A material classification device for separation of solid materials, having a relatively high specific gravity, from a stream of fluid and solid material. The device is particularly suited for the extraction of gold from alluvial material. The device generally comprises an open conduit that has a first opening and a second opening therethrough. A container is attached to the bottom of the conduit so that the openings are in fluid flow communication with the container. A portion of the flow of fluid and materials passes through the first opening and is captured in the container. A tube passes into the container with an aperture therein so that a fluid may be passed into the container to agitate the material collected therein freeing the lighter material so that it can exit the container out the second opening.