A sapphire by any other name.

“Natural sapphire, natural color,” is the conclusion of the Gemological Institute of America Gem Trade Laboratory Identification Report on the 80-plus-ct. transparent pinkish-orange oval mixed cut shown below. Dr. Eduard Gübelin’s personal Quality Report from 1995 reads: This gem is “probably the finest in the world.”

Big, beautiful, saturated, naturally colored sapphires are difficult to find. Sapphires from Sri Lanka and Madagascar are well known for having been heat treated. This is especially true of blue and pink corundum. Sri Lankan blues commonly begin as a yellow-milky (cloudy) white colored crystal termed Geuda. Heat-treating Geuda material produces exquisite, transparent brilliant blue sapphires. Heat-treating other sapphire colors-like the light pink Madagascan material-helps to deepen and saturate the inherent color of the gem. Because the process is permanent, inexpensive, and easy, creating beauty in a gem with weak or nonexistent color is as obvious a step as faceting and polishing. It’s believed that 99% of all saturated blue and pink sapphire is heated.

So finding a fine-quality naturally colored sapphire is a coup. Size and clarity of colored gems is important, but when combined with unenhanced saturated color, you have a rare and valuable gem. Blue sapphires are considered the most popular, and therefore most valuable. The most sought-after blues-from Kashmir, India-boast an electric “cornflower” color. Thanks to the Kashmir sapphire, locality has become an important descriptor. Exotic localities add to the gems’ importance. For example, Yogo Gulch, Mont., produces gems with a Kashmir-like color, yet, because of their U.S. origin, the stones may not command as high a price as the Kashmirs.

Pinkish-orange sapphires are second in value to blue sapphires, but not when they’re merely “pinkish-orange.” In this color range, larger sizes-like this 80-plus carater-are much rarer than large blues. That means the value of a big pinkish-orange can surpass that of many fine-colored large blue sapphires, as size becomes important. This particular gem is one-of-a-kind in this size and can command just about any value based on demand.

The pinkish-orange sapphire has been identified by the Gübelin laboratory as having come from Sri Lanka. As noted, exceptional naturally colored Sri Lankan sapphires are rare. And while this is important, the gem’s place of origin does not necessarily create greater value. Again, we go back to the actual color-pinkish-orange.

When pink and orange combine to create a particular hue, the results are highly prized. Many sapphires do not have enough pink or orange to be considered this hue. And while the color of the rough crystal may not exhibit both colors together, a master cutter can fashion a gem that not only keeps both colors in one stone but also brings out both colors, face up and merged properly into one hue. Such a sapphire is affectionately known by another name. And when referred to as such, because of its mysterious and exotic descriptor, the pinkish-orange sapphire commands a much higher price.

Question: What is it called? (Answer on p. 226.)

Answers to “Grade This: questions on page 80:

A. “The composition of the two inherent hues orange and pink in correct proportions results, indeed in the true and highly prized Padparadjah hue, which is a pure orange with a slight tinge of pure pink.”-Dr. E. Gübelin.

B. According to the GTC laboratory, there is no evidence of heat treatment. That determination is based on the fact that the silk remains as long thin needles and the crystals are still intact. If the gem had been heated, the silk would have melted and recrystalized into strings of tiny dots, giving the stone a slightly better clarity. The crystals would have expanded, creating halo stress fractures surrounding each inclusion. Because these two inclusions are still complete, it can be concluded that the gem remains the way nature created it.

Special thanks to Evan Caplan, Evan Caplan & Co., Los Angeles, and John Bradshaw, Coast to Coast, Nashua, NH.