Manganian, ferrian andalusite (viridine) occurs abundantly in kyanite-hematite quartzite of the Precambrian Kiawa Mountain formation at Kiawa Mountain, Rio Arriba County, New Mexico. Its extraordinary pleochroism (golden yellow to emerald green) results from the copresence of Mn+3(Mn2O3 = 4.5%) and Fe+3(Fe2O3 = 3.0%). The andalusite apparently formed essentially contemporaneously with the kyanite.

This content is PDF only. Please click on the PDF icon to access.

First Page Preview

First page PDF preview
You do not currently have access to this article.