We descended hunched over, down a long, steep, wooden staircase to the 1,000-level.

Because the forces of erosion and gravity tend to carry lighter materials like quartz away more easily, the heavy minerals like gold or silver will tend to be concentrated in the general area around the vein outcrop. These concentrations are what make residual placers so attractive.

The largest and most perfect single gold crystals are nearly always in the form of octahedra. These large octahedral crystals often possess deeply recessed faces.

Has your experience ever led you to wonder why some gold is deposited on bedrock and in crevices, while other gold is not? We’re going take a deeper look at this and see what we can figure it out.

In this second part on cobalt, I will take a look at the various types of cobalt deposits and how you can prospect for them. Who knows—perhaps the next big cobalt strike will be yours.