‘Rubies are red, sapphires are blue…. except when they are green, purple, yellow, pink, orange, or chocolate.’ Wait, what? Chocolate?!? Yes indeed, thanks to the marketing gurus, your jewelry box can also contain chocolate sapphires. Who knew?
Technically, corundum gemstones are all one big happy family with only two proper names: Red corundum stones are called rubies. A corundum of any other color is a sapphire, and these can be any of the colors I just mentioned, as well as black, white, and almost colorless. Because blue shades are the most common, we call that group ‘sapphire’ and lump the other non-red stones together as ‘fancy sapphires.’
The different colors are a result of trace elements found in certain stones. A blue sapphire looks blue because it contains traces of titanium, which reflect blue light back to our eyes. If that stone had chromium instead of titanium, we’d see it as pink. Different combinations of trace elements will produce different colors and shades of colors. Vanadium will result in a stone that will appear to change color according to the type of light (daylight, incandescent, fluorescent, or LED) present in its environment. A corundum completely devoid of any trace elements will be colorless.
So, what produces brown (or chocolate, in today’s parlance) sapphires? Iron is definitely present, as it is in orange and red-orange stones as well as in rubies. As you might expect, there is a range of brown shades, depending on the type and quantity of the non-iron trace minerals in a stone. Red-orange sapphires are usually called “cognac” but browner ones (with less orange) are not; when of good quality, these stones are usually marketed as ‘chocolate.’
All of these would be classified as brown sapphire in the trade, although I personally would only describe the one at the far left as ‘chocolate.’
This is a rough, uncut piece of chocolate sapphire. In culinary terms, this would probably be a piece of Valrhona 70% Dark! This 57-carat (not a typo) piece of rough sells for about $30.
In contrast, this is a cut (faceted) stone. It came from Sri Lanka, weighs 1.70 carats, and has been heat treated. The inclusions are described as “very light”, although there may have been more before the heat treatment.
The major determinate of quality in a chocolate sapphire (other than the color itself) is clarity; they need to be ‘eye-clean’, i.e., without any visible inclusions, in order to be considered gem quality. Such stones are more likely to be found in Sri Lanka, Madagascar, Australia, Tanzania, and Thailand.
That said, many people find included stones to be more interesting; they are certainly more numerous and far less expensive than gem-quality examples! Here is an affordable, mass-produced ring set with a brown sapphire with inclusions, commonly called ‘needles’.
If the needles are of the mineral rutile, and occurring in intersecting groups as some of these examples have, they are called “silk.” Chocolate sapphire is somewhat of an exception to the general rule that inclusions always lower the value of any type of stone, because they make the stone appear more opaque or ‘silky’…. more like a milk-chocolate appearance.
Nerd Note: An alternate name for brown or chocolate sapphire is Adamantine Spar, described as a ‘silky brown corundum’.
There is also a type of natural brown sapphire, found in Kenya, dubbed ‘Golden Sheen’ because of its unique metallic-shine appearance; it is also called Zawadi sapphire. Most of these are in the yellow/blue/green color family, but some are brown. They are heavily – dramatically, really – included with needles and platelets of hematite and ilmenite in addition to the iron component.
All four of these sapphires are heavily included, but only three of them would be marketed as ‘chocolate.’ On the other hand, quite a few brown/chocolate sapphires may be advertised as ‘gold sheen’ that probably don’t deserve that description.
Treatment of Chocolate Sapphire
Heat treatment is fairly common on all colors of sapphire and will have different results depending on the properties of a given stone. For example, it might dissolve some inclusions and thereby make the stone less opaque/cloudy. Or the heat might slightly change the chemical properties of the inclusions, via oxidation, which in turn can alter the stone’s color. A sapphire that is “too dark” of a blue can be lightened via heat treatment. Heat treatment can be detected by a gemologist with the necessary equipment, although not by the naked eye. Sellers should disclose any heat treatment, in the interests of transparency (no pun intended!)
Another possible treatment is diffusion, whereby a specific mineral is added to the surface of a faceted stone (think of it as ‘painting’ the surface with something) and then heating it so that the mineral diffuses into the upper/surface layer. That is enough to change the appearance to human eyes. For example, a pale blue sapphire’s color can be deepened by applying Titanium and Iron oxides to the surface and then heating it. This treatment is not obvious to the naked eye but can be detected by professional methods. Because diffusion is a longer process than basic heat treatment, it is unlikely to be done on less expensive stones such as the brown sapphires.
Chocolate Sapphire Jewelry
Although the GIA doesn’t recognize “chocolate” as a sapphire color, it certainly makes for a more appealing seller advertisement! Because of its hardness (9 on the Mohs scale, only one step below diamond) any sapphire is a great choice for rings.
In this pendant, the central chocolate sapphire has been combined with smaller smoky quartz above and around it, and white zircons substitute for diamonds. The setting is rhodium-plated sterling silver instead of white gold (which would be overkill for non-precious stones), providing a hefty serving of glitz. The sapphire’s 2.5 carats make up part of the pendant’s total 4.39 carat weight.
Unfortunately, the carat weights and specifications were not available for this pretty ring. I would consider this more of a cognac than a chocolate color, though.
On the opposite end of the glitz spectrum is this ring that focuses attention on the rose-cut chocolate sapphire. The band is sterling silver but the rest of the ring mounting is 14k gold.
Sterling is often used for affordable jewelry and has the added benefit of being easily formed into intricate designs (although less easy to keep tarnish-free.) The purple side stones are rhodolite, a trade name for pyrope which is in the garnet family. Shades of rhodolite vary from pink to magenta to violet-rose. This ring weighs slightly more than 10 grams, including the stones and mounting.
This interesting Native-American-style necklace combines two chocolate sapphires in a sterling silver mounting that (to my eyes at least) resembles an arrowhead; it is 40mm high and 21mm at its widest point (about 1.5” x 0.75”.) The 17”-long necklace is a combination of Amazonite and sterling beads.
The combination of chocolate with blue-green is very effective, as shown in this pair of earrings pairing chocolate sapphire with Nevada turquoise. These are two inches long.
A very dark chocolate sapphire is surrounded by a ring of white topaz, with ‘neon’ apatite set into the sides of this sterling silver ring.
This chocolate sapphire has an uncharacteristically deluxe setting: the bezel is 22 kt gold, as are the five groups of 22 kt gold ‘dots’ accenting it. In the largest ‘dot’ of each group is a tiny champagne-color diamond. Oddly, the band is sterling silver; I’d have thought that the maker would have chosen 14k white gold instead.
This ring is a veritable Chocolate Shoppe because it is simply loaded with chocolate sapphires! The center stone is just shy of 11 carats, and the total carat weight is 18.82. The setting is sterling silver. That’s a lot of chocolate. This looks like milk chocolate to me; what do you think?
The style of this unusual pendant is called Mokume–gane which is a Japanese metalworking procedure based on laminating and mixed metals. The word translates roughly into “wood grain metal”, meaning that the metal component ends up with a wood-grain appearance…as can be seen in the narrow strip between the two silver bars attached at the base of the chocolate sapphire’s setting (which is approximately 2.5” x 1.75”.) The mounting and adjustable 16”-18” chain are sterling silver.
Carved Chocolate Sapphires, and Beads
Not exactly jewelry, per se, are carved brown sapphire stones. I am sure that some could be made into pendants and brooches but these pieces are usually sold individually, as shown in the examples below. This is perhaps the most similar to an actual piece of chocolate in appearance, and they are hardly ever treated in any way.
This owl face is about 1.25” x 0.75” and a little more than one-quarter-inch thick. It weighs about 41 carats and would make a cute brooch for an owl-lover!
These two examples of a carved chocolate sapphire rose show the variation in chocolate shades. They weigh a little more than 46 carats and are about 1.5” high and one inch wide. Like the owl, they are about ¼ inch thick.
A quick search for ‘carved chocolate sapphire’ on Google, Etsy, or eBay will bring up a healthy number of examples in almost any motif you can think of.
Chocolate sapphires are also cut and polished into beads. Typical shapes are round (top photo), coin (lower left), and faceted (bottom right.)
These teeny-tiny beads are micro-faceted by a laser. A 12- or 13-inch strand of such beads typically sells on Etsy for $20.
Although they will never have the upscale cachet of chocolate diamonds or even their ruby-red ‘cousins’, chocolate sapphires can definitely be an interesting casual-wear addition to the chocolate lover’s jewelry box!