The pink zones in blue to blue-green, copper-bearing tourmaline gemstones were manufactured by fluids having naturally occurring radioactive material which is found by gemological Institute of American Laboratory.

The GIA lab members, replied to concerns in the trade over samples of these meticulous tourmalines with surface-reaching growth tubes surrounded by intense pink "sleeves," investigated more than a few of these tourmalines in the previous year.

In all examples where pink coloration was examined, the growth characteristics surrounded by the pink color reached the layer of the stones, in accordance to the GIA lab team led by chief gemologist John I. Koivula. In some situations where development tubes did not reach the layer, no pink color was seen. When these pink zones were viewed down their length, the color was noticed to bleed out into the surrounding tourmaline host, becoming feebler until it slowly loses its color. If post-growth matter in the tube made a blockage, coloration happened only to that point. Additionally, any cracks extending from or amid the growth tubes also showed a pink color.
Radiation is known mainly to manufacture pink-to-red color in tourmaline. The coloration of surface-reaching features in tourmaline by invading radioactive liquids has not been reported in the literature; nevertheless, there have been reports of both smoky quartz and green diamonds with coloration that was caused due to exposure to logically happening radioactive fluids. This mechanism explicates all the observations of pink and red in these tourmalines.

Koivula stated that as the radiation is the major cause of pink color in the tourmaline, the presence of these characteristics must not be attributed to any kind of intentional diffusion yet instead to the influx of radioactive fluids in their post-growth environment.

All the copper-bearing tourmaline samples with this feature observed therefore far have come from Mozambique. This recommends that this kind of inclusion feature can be characteristic of that area.

The presence of the pink zones in these or else blue to blue-green gems also gives proof that the host tourmalines were not heat treated, as the temperature required to treat copper-bearing Mozambique material crosses the published stable temperature for pink-to-red color in tourmaline, the lab team said. Kevin Nagle, Andy Shen and Philip Owens are the other members of the lab team who got involved in this investigation.