Mineral specimen mortality

Efforts to dissolve unaesthetic minerals from more desirable ones can often go awry when both species are attacked. In 1974 a collecting buddy (Bob Bartsch) and I (RHC) went to the inesite locality at Hale Creek in northern California. With considerable effort we broke up the typical calcite and inesite boulders found in the creek bed and selected about two hundred pounds of specimens of the calcite intergrown with inesite that showed the greatest etching potential. We had to haul this material by backpack about three miles to our vehicle. Al McGuinness, another dealer/collector, told us that he used a very weak solution of hydrochloric acid kept very cold to remove the calcite. Try as we might, we could not get the solution to etch properly and we ruined many specimens. Finally we tried nitric acid which worked wonderfully even in concentrations as strong as 20%. We have also found that, if calcite must be removed from dioptase, nitric acid is the acid of choice, and that most other acids (even acetic acid) will remove any existing luster from the dioptase.

Preservation techniques gone wrong can also destroy specimens. John Mediz regularly collected wulfenite at the 79 mine in Arizona, and on one trip was fortunate to recover over 250 fine but very delicate specimens on a rather crumbly matrix. These he offered to another mineral dealer, Chris Wright. Questioning the friability, Wright was told that all he had to do was dip the soft rock in a plasticizing solution and it would stabilize and harden the matrix. But there was a misunderstanding in the communication of this technique; Wright dipped the entire specimen in plastic solution, rather than just the friable matrix, and the crystals of wulfenite became plastic-coated in a most obvious and unattractive way. All subsequently had to be discarded.

Chemical damage is not always of the corrosion type. Many dealers will remember the 1989 Springfield, Massachusetts, Gem and Mineral Show, held at the Civic Center in downtown Springfield. Normally some inclement weather on show weekend would be considered a plus, as attendance would increase when outdoor activities are curtailed. That weekend it rained. And rained, and rained and rained. Dealers went about their business on set-up day and then retired to their hotel rooms for a good night's sleep before the show opening. All-night guards patrolled the otherwise deserted show floor. And still it rained. Although the show floor was about six feet below street level, the entrances were well designed, and not a drop of the water that was flowing torrentially down the streets and sidewalks outside got in over the doorway thresholds.

Unfortunately the heavy rain was overloading the city's storm drainage system. Finally, at around midnight, the whole system suddenly backed up. Drain plates set into the concrete floor of the Civic Center were blown off and, according to stunned security guards, geysers of rainwater shot 20 feet in the air from the drains. Within moments the show floor was flooded and the water was rising. Most dealers had stock stored under their tables in stacks of beer flats, as always. The water level rose to one flat deep (about 4 inches), then two flats deep, then three. Finally the city engineers got the problem under control, the geysers tapered off, and the water began to recede.