Identifying Microscopic Minerals from Mapimi, Durango, Mexico

摘要

Since I arrived in Texas in 1963, the colorful Mapimi secondary minerals were readily available to collectors from dealers, flea markets, and recycled collections. They were particularly abundant in the 1970s and most of the 1980s, but since then supplies have been more sporadic. They still can be relatively plentiful and inexpensive if you know what you are looking at. True, outstanding specimens and rarer minerals with larger than microscopic crystals are now quite expensive, but there are a lot of specimens available with spectacular small examples of common and some rare minerals. Specimens from "old garage collections" are usually battered and dusty, but if they contain unexposed cavities or undamaged areas, treasures may be found that make them worthwhile. Often a specimen with more than one or two minerals on it is usually sold by the name of the most dominant or easiest to identify or even misidentified mineral. A closer look may be warranted for the unexpected rare mineral or super microscopic specimen.