Quartz Pseudomorph After Baryte
Cabinet, 8.7 x 5.2 x 3.0 cm
Silverton Dist., San Juan County, Colorado, USA

This is a classic example of one mineral species replacing another. A druse of colorless, quartz crystals has totally pseudomorphed a classically formed, tabular crystal of Baryte. This is easily one of the nicest examples I have ever seen of this process involving these two species.