In Gorham, New Hampshire there is an old lead mine named the Mascot Mine that recently has gotten a lot of attention from micromounters. In addition to lead mineralization in the form of galena; copper, zinc, and iron minerals are present and abundant as primary phases (chalcopyrite, sphalerite, and pyrite). When these metal sulfides oxidize from weathering, an impressive suite of secondary minerals can form. This is the case here.
            The Mascot mine satisfies three criteria for making it an important locality for micromounters. First, a large number of minerals can be found there in attractive microcrystals. Secondly, they often present challenges in identification. (If identification were easy, we would never learn much about minerals.) And finally, the Mascot suite of minerals raises interesting questions about how minerals form.
Included among the mineral species identified from the Mascot mine are uncommon to rare minerals such as schulenbergite, posnjakite, serpierite and also the possibility of claraite and lanarkite. With this assemblage the locality takes on a European flavor. These minerals are rare in the United States but occur at several localities in Europe, a number of these being slag localities. The best example is at Laurium, Greece where ancient miners threw processed ore slags into the ocean. When these boulders wash up on the beaches they often feature microcrystals of exotic secondary minerals. Mineralogists have long disagreed as to whether these can actually be called minerals. In the definition of a mineral is the phrase "naturally occurring". There is nothing natural about processing metal ores and throwing them into the ocean, a foreign environment. The hand of man clearly is involved. At the Mascot mine the situation may not be that extreme; however, much of the mineralization is post-mining in origin, occurring on the surface of dump rocks that were placed in a pile by man and allowed to weather. There is also the question of whether the pond contributed to mineral formation. The most productive dump at the locality is at the edge of Mascot Pond. Perhaps it was at that spot that the miners cobbed the ore. At its deepest spot the dump is more than five feet deep. Water is hit at the bottom, yet, the dump rocks are wet by capillary attraction two to three feet above this. Maybe constant moisture helped solutions supersaturate with metal ions for at this deepest part of the dump, solution driven surface mineralization is widespread.
As a contributor to Van King's upcoming book "The Mineralogy of New Hampshire" I will at some point in time have to wrestle with the post- mining question. In the introduction to Van's "The Mineralogy of Maine" it is clear that he doesn't feel that minerals formed on the dumps reflect the geological and chemical processes of the state and are not suitable for inclusion in the book. For example, if the mined Mascot material were moved to the edge of a pond in Vermont, we would be talking about schulenbergite from Vermont. In the case of the Mascot minerals some may have formed both in place within the ore vein and also as a post-mining druse. It will be difficult to sort this out.
A bizarre twist occurred regarding the mineral acanthite, a silver sulfide that forms as flat bristles upon wire silver on some Mascot specimens. Scott Whittemore approached me one day and he said "I think my acanthites are growing." He looked in all directions before stating this to make sure no one else heard such crazy talk. Later I checked my own acanthite specimen and found the crystals to be about three times larger than before. I also found acanthites starting to grow on silver wires that previously showed no acanthite. Post mining is one thing, but post-collecting mineralization brings this thorny problem to a level of absurdity.