is a rare member of the Calcium Amphibole Subgroup of
minerals that also includes Actinolite,
is very rare and
obscure mineral and only found in one place in the world - the Greenwood
Mine in the Town of Tuxedo, Orange County, New York, USA. It is rarely found
in mineral collections and even rarer as a faceted gem!
It is black with vitreous luster and is barely
radioactive due to its potassium content.
was discovered in 2005 in the tailings dump of
the Greenwood (Patterson) iron mine. The mine, located
in Hudson Highlands, in Harriman State Park, Town of
Tuxedo, Orange County, New York, USA, was first opened in
1838, and was a source of iron during the Civil War.
It was last worked in 1880.
mineral was originally named Fluoro-potassic-hastingsite
in 2009 by Marian V. Lupulescu, John Rakovan, M. Darby Dyer, George
W. Robinson, and John M. Hughes for its chemical relationship to
Hastingsite. But it was redefined and renamed in 2012 by the Amphibole
Subcomittee of the Commission on New Minerals, Nomenclature and Classification (CNMNC).
The new IMA approved name is Potassic-fluoro-hastingsite
following the principle that the various
prefixes to the root name are listed in the order they occur in the formula.
gems for sale:
have not photographed our Potassic-fluoro-hastingsite
check back soon.