Museum Moment - Amphiboles

Uploaded by nysmuseum on 01.12.2010

I am Marian Lupulesco, I am curator of geology with the New York State Museum and my responsibilities
here at the museum are the curation and research on the mineralogy collections. One of my research
interest is the amphibole group minerals. The amphiboles represent a group of very complex
mineral composition and they are found in some metamorphic and igneous rocks. Also in
ore deposits and they are also found in meteorites. In these three boxes we have the same amphibole
that is called tremolite. The color is different from a box to another one. Here this lavender
color is given by trace amounts of manganese and the bright green color is given by trace
amounts of chromium. Some of the amphiboles show visible light when they are hit by ultraviolet
or by other electromagnetic radiation. This property is called fluorescence. These two
amphiboles, Parvo-mangano-edenite found in St. Lawrence County and Fluoro-potassichastingsite,
found in Orange county are only from New York. They are never found at this moment in other
countries. If you want to learn more about minerals and especially about amphiboles please
visit us at the New York State Museum.