A New Occurrence of Allophane From the Laochang Mine, Gejiu City, Yunnan, China

摘要

A recent acquisition of exceptional allophane specimens from the Laochang Mine (see figure 1) came as a complete surprise. Our agent in China had located a modest supply of brilliantly colored, electric blue material labeled as "gibbsite", and selected only the most colorful specimens for hand-carrying back to the U.S. Knowing there has been much controversy regarding the presence of gibbsite (Al(OH)3) and/or evansite (A13(P04)(OH)6 ? 6H20), two similar appearing minerals from other Chinese localities that can be easily differentiated by chemistry, it was time to clear up the confusion. Hence, it was important to analyze these specific samples to be certain of their identity, even though neither species had previously been reported from this mine, best known for itspale blue hemimorphite.