Betafite (ex Chet Lemanski Collection)

Item Description

Please note that Betafite is no longer a valid species, and as far as I can tell it's part of the Pyrochlore Supergroup, but the listing on mindat.org states that,

"True "Betafite" samples are structurally members of the pyrochlore supergroup. Hogarth (1977) stated that the betafite group has 2Ti ≥ (Nb + Ta), however the formulae of most betafites do not exactly correspond to pyrochlores and that difference has delayed their classification.

The result of modern microprobe analyses is that almost all specimens formerly labeled betafite are no longer members of that group. New analyses, including determination of H^2O, OH, and F are necessary to identify the species of a particular sample. The root-name, betafite, was retained for historical reasons".

With that said, this piece is a great example of what was known for years as Betafite featuring fairly sharp, well-formed, cuboctahedral crystals measuring with a dark reddish-brown hue, free of matrix. Good quality, though slightly rough in a few spots. From the collection of Chester ("Chet") S. Lemanski Jr. of Browns Mills, New Jersey (https://www.mindat.org/user-461.html). Collection #1609CL. Chet was born 1947 in started collecting minerals circa 1957. He worked briefly as a drill runner at the famous Sterling Mine, in Ogdensburg, New Jersey and from 1987 to 1990 he helped convert the mine into a public access mining museum. He has held the role of treasurer, vice president and president of the Franklin-Ogdensburg Mineralogical Society (FOMS), and has been a board member and vice president of the Franklin Mineral Museum. The rare copper arsenate, Lemanskiite was named in his honor in 1999.