FeatureGems & Gemology, Spring 2009, Volume 45, No. 1
Solution-Generated Pink Color Surrounding Growth Tubes and Cracks in Blue to Blue-Green Copper-Bearing Tourmalines from Mozambique
John I. Koivula, Kevin Nagle, Andy Hsi-Tien Shen, and Philip Owens
Several transparent, faceted, blue to blue-green copper-bearing tourmalines containing growth tubes and cracks surrounded by sleeves of pink color were examined for this report. On the basis of micro-observation, it is theorized that a radioactive solution was the probable cause of the pink color. The presence of the pink zones also supplied visual evidence that the host tourmalines had not been heat treated.