Mineral Specimen Diseases

摘要

Many collectors have observed physical changes in mineral specimens over time. Marcasite, one of the better known minerals with poor staying power, will often end up as a lump of powdeiy white crud if not stored properly. When laced among the seams in typical pyrite or galena specimens, these, too, will decrepitate over time, rendering a once-attractive specimen into something destined for the trash (see figure 1). This physical change is one of several "mineral diseases" that afflict certain specimens. Identifying what the residual mess really is, and perhaps developing some techniques to forestall it, make for interesting pursuits in themselves.