The Roebling Apatite, Pulsifer Quarry, Androscoggin County, Maine.

Cathodoluminescence (CL) measurements from a few single crystals and fragments of Pulsifer apatite in general showed areas of bright yellow-green CL emission corresponding to pale purple or white parts of the apatite. Purple apatite is a rare variety of fluorapatite that is widely distributed in many rock types. Description of the Roebling Apatite The Roebling apatite is considered by many mineral collectors to be one of the finest specimens of fluorapatite ever discovered. The best purple apatite specimens were mined from the Pulsifer quarry and include the world-famous Roebling apatite, which currently resides in the mineral collection of the National Museum of Natural History, Smithsonian Institution (fig. 1). [Extracted from the article]