Andalusite Gems Stone Engagement Ring 22

                       ANDALUSITE STONE
By Aamir Mannan.

 The brownish green andalusite showing a himt of red, which are rare enough to be sought-after by collectors, may show an absorption band in the blue at 4550 A, but it is not very enough reliable as a test. quite a different spectrum is seen in a rare green type of the mineral 

from  Brazil. Because of the extreme fineness and delicacy of the bands, this was formerly assumed to owe its absorption features to some unidentified rare earth. But this beautiful spectrum can now be ascribed to manganese, and was reported as a feature of viridine a manganese rich form of andalusite. In 


this spectrum there is a sharp edge of  shadow at 5255 A in the green, shading away on the yellow sidewhile on the other side is a narrow line at 5495 a.