Silver nuggets have been described as “ultra-rare,” “prized” and “unique.” Naturally occurring silver nuggets are rare enough to suggest caution when purchasing. Fakes have reportedly been produced and misrepresented for sale as genuine specimens.

The gravels in contact with the bedrock or false bedrock base are often the richest. The same facts apply to the alluvial paystreaks that are formed on gravel bars; the lowest level of the gold-bearing gravel is normally the richest.