Check out our all new Speed Flare for your current sluice box! The Speed Flare allows you to classify directly on top! Click the image to take you to the store.
It will catch just about any mineral but of course the heavier metals will separate out easier. Just a matter of determining the amount of flow/angle needed to retain the desired minerals and chuck the dross out the end. Personally I'd rather retain a bit more junk that I can sort through at home than try to separate it out to just metals/minerals in the stream. For me my sluices' job is to reduce buckets of gravel down to a small amount of cons to clean out at home.