Calcite Butterfly Twins on Matrix

Unknown Owner

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This is perhaps the most famously known (and expensive) specimen in the collection, as it was shown at an exhibit on twinning in Munich of 1999, and is published in both the widely circulated German Lapis issue on Calcite; and the English-version ExtraLapis issue on calcite (2003). It is a miracle survivor, in that it has lasted all this time since being mined in the mid 1800s, and remains in nearly pristine condition. This specimen hosts FIVE butterfly twinned calcite crystals on matrix. Interestingly one closed twin (i.e. the wings taper in, instead of out) has formed between 2 open twins, in the first three crystals in front...how this could happen, two different twin laws forming on crystals growing at the same time in the same place on the same matrix, I have no idea. Certainly it is unexpected. The specimen was formerly in the collection of wealthy sauerkraut manufacturer K. Rau of Germany, who specialized in highest quality cabinet pieces. A previous and clearly older German label notes that the specimens is "selten schone xx stufe" - a "rare and beautiful crystallized piece!." Upon his death, the piece went to Humboldt University of Berlin. It was exchanged out in 1986 and shortly ended up with Ralph Sutcliffe, whose collection passed to the Greenbanks in 1991. The previous owners feel that this specimen is the most historically important calcite in this collection, and one of the most important calcite survivors from the heyday of British mining, period. I am, simply, honored to offer it. As a young collector specializing in calcite since I was 12, this is really a dream come true to hold this famous specimen! Illustrated multiple times as noted above in other journals; and on page 117 of our own book on this collection, Minerals of Northern England. Joe Budd photo.