Pink sapphires have become more widely available since new deposits were found in Madagascar in the late 1990s. Until that time, pink sapphires were considered exceptionally rare since they were only found in a few locations around the world including Sri Lanka and Myanmar.
Most pink sapphires have the typical inclusions found in corundum. Eye-clean, untreated stones are available on the market, but the majority of these have had their clarity enhanced by heat treatment. Because pink sapphires are rare, stones half a carat or more are not cut into calibrated sizes. Instead, each will be cut to retain as much of the rough as possible. Most are given a mixed cut. The most common shapes are rectangular and square cushions or ovals.
Pink sapphires come in very pale baby pinks to vivid, almost magenta, intense pinks. Right now, the most coveted pink sapphire colors are highly saturated purplish red hues with a medium tone—these are often described as “hot pink” or “bubble-gum pink.” Pink corundum is colored by traces of chromium. Very high chromium concentrations will create a ruby, and lower concentrations create pink sapphires. If the trace element titanium is also included in the crystal structure, the sapphire will have a more purplish pink hue.
Many of the sapphires from Madagascar are subjected to moderate heat treatments to reduce their purplish secondary colors. The heat treatment protocols employed are very different from the traditional long duration, high temperature heating of blue and yellow sapphires. Blue and yellow sapphires are heated at extreme temperatures (up to 1800º C) for 3-10 days, often along with color and clarity enhancing additives. Madagascar pink sapphires, on the other hand, are heated at temperatures far lower (about 400º C) for only a few hours. This “gentler” process does not alter the internal characteristics of the gemstone which makes the detection of heat treatment more difficult for the gemologist. Madagascar pink sapphires can be heated for as little as five minutes at low temperatures and no internal inclusions are affected. High heat temperatures affect the inclusions drastically.
Although some success in detecting this treatment has been achieved by employing high tech equipment to detect trace element changes within the stone, the equipment is costly and beyond the reach of the average gem laboratory. It is still a new science and in many cases, it can be very difficult to determine if a pink sapphire from Madagascar has been heated. Even the most respected professional laboratories have been known to disagree when evaluating the same gemstones. We have given multiple laboratories the exact same Madagascar pink sapphire for testing to determine if it had been heated or not. We were given conflicting results on the same stone from different laboratories. One said that the pink sapphire was heated and the other not heated. The reputable laboratories often do an excellent job, but just like determining origin, whether or not a pink sapphire from Madagascar has been heated is a difficult task.
This pink sapphire has two conflicting report results. One specifies no heat treatment, while the other assesses the sapphire to be heated.
Read more about Sapphire Origins.