Written 1995-Updated 1997, 2017, 2018

by Robert G.Genis

In the mid-eighties, the Hancock family faced a dilemma. As heirs to a ranching family, they owed the IRS approximately $1 million. Although the family business was asset-rich, they were cash poor. They did not have the money to pay the IRS. The choice was either sell the family business, or sell Mr. Hancock's collection of colored diamonds that he had been hoarding for years. Everyone in the family thought the patriarch was a little crazy for collecting diamonds; but it was his money so what could they say? He enjoyed his colored diamond collection.

The heirs loaded up his entire collection of hundreds of colored diamond and sent them to Christie's of New York. They were hoping the selling of all the colored diamonds would help offset some of the tax due. They explained their situation to Christie's. To their surprise, Christie's chose three diamonds, and sent the rest back! The three stones were a .95 red, a .59 purple-pink, and a .54 reddish purple.

On April 28, 1987, at Christie's of New York, an agent allegedly representing The Sultan Of Brunei bought the .95 red round diamond for $880,000, plus a 10% buyers commission. This set a new world per carat price for any gem that remains today-$926,000 per carat. The previous record was $127,000 per carat for a 7.27 pink diamond in 1980. During the same 1987 auction the two other stones also sold: the .54 fancy reddish purple diamond for $65,880 or $122,000 per carat, and the .59 purple/pink went for $135,000 or $229,000 per carat.

Needless to say, the auction house sent the heirs over $1 million which was used to pay off the IRS debt. Not only did this save the family business, but the family retains over 99% of the original colored diamond collection. Another amazing fact is that Mr. Hancock bought all of the diamonds from his local jeweler at retail prices. The jeweler would routinely mark-up the stones 100% before selling the stones to Mr. Hancock. All three diamond were purchased in the 1950s and were said to be from Brazil. Mr. Hancock paid $13,500 for the .95 red that sold for almost a million dollars. Mr. Hancock had less than $20,000 into the three diamonds that sold for over a million dollars.

What are the lessons to be learned from this true story? First, collect what you love. Maybe in the back of Mr. Hancock's mind he planned to sell the stones someday to make a profit. However, he just acquired a fascination for colored diamonds and never sold any of them. His pleasure came from buying and owning colored diamonds. Secondly, Mr.Hancock bought colored diamonds relentlessly. It mattered little to him about price increases or price decreases. He bought consistently. The business cycle was irrelevant to Mr. Hancock. If he had the money he bought. He did not care if the US economy was in an expansionary or recessionary phase. As a matter of fact, when prices dipped, his dollars went further in a down market.

Not everyone will experience the phenomenal success of Mr. Hancock. However, if you read the following article, your chances of success will rise geometrically.

Alexandrite from any source is one of the world's rarest gems. Reportedly, this gem was discovered on Czar Alexander the Second's birthday in Russia in 1830, and hence its name. This is one of the few gems that actually change color. The stone appears green like an emerald in natural daylight, and ruby red in artificial light. Interestingly, these were the colors of the Russian Imperial Guard. The deposits of the Ural mountains were depleted long ago.

Tiffany was instrumental in marketing Russian alexandrites to Americans during the 19th century. Tiffany liked to sell large alexandrites that were mounted as center stones. Most of these stones are in family vaults and are passed generation to generation. These stones are extremely difficult, if not impossible, to buy today.

In an ideal perfect world, alexes change from red to green. However, this is not usually the case. They tend to change from a brownish reddish raspberry to a grayish bluish green. Some stones only partially change color. What you are looking for is a dramatic 100% change.

Today, the main sources of alexandrite are Sri Lanka and Brazil. Collectors have long complained about the Sri Lankan stones. They either had brown or yellow undertones, or they did not have a color change, or were horribly included. The largest known alexandrite is a 66 carat Sri Lankan gem currently in the Smithsonian Institute. From a collector standpoint, there is some of this material available today.

In 1987, a new find of alexandrite was discovered in Nova Era, Brazil. This country has always been known as a producer of inexpensive gems, until this find. What was amazing about this find was that most of the Brazilian gems had a 100% color change. Although they did not change from ruby red to emerald green, they changed from a pleasing raspberry red to an electric blue green color. Presently, there is some limited availability of these goods today.

When collecting alexandrites, remember the color change is everything. Clarity is a minor issue, as long as the inclusions do not effect the gem's durability. Also, cut is not critical, as long as the stone is not so shallow or deep that it affects its sparkle.

One caveat is due here. If you have never seen an alexandrite, you may be disappointed. If you want a perfect stone for jewelry, you can buy a synthetic alex for $100 per carat. They have a perfect color change, are cut perfectly, and are flawless. However, if you are a serious collector, this is one stone to collect, and love for what it is. Alexandrites are one of the most sought after gems.

Jewelry quality alexandrites begin at $1000 per carat. Wholesale prices range from about $8000 per carat for a gem quality Brazilian gem to over $50,000 per carat for a five carat Russian gem. Average prices range from $5000-$20,000 per carat.

Although most tourmalines are not worth collecting, in the 1970s two mines were discovered by African miner Ali Giowatta in Tanzania. These gems do not look the like the somewhat ugly green tourmaline from Brazil. The reason is due to the fact they possess chromium. In its top colors, chromes resemble gem tsavorite (See Tsavorite). The former owner was poisoned in 1980 by his mistress, and his three former wives have been fighting over the mines ever since. This feud causes production to be sporadic. There is just enough production to keep the aficionados loyal, and the prices the highest paid for any tourmaline except Paraiba.

Like tsavorite, top chrome greens are rich, bright, and clean green. It is very difficult for novices or experts to tell the difference between fine chromes and tsavorites. Some fine chromes tend to possess a greenish/yellow cast. Others are definitely greenish/blue. Which color is the best is strictly personal preference. Although chrome tourmaline is scarcer than tsavorite, they occasionally come in 10 carat sizes, which tsavorites do not.

These gems should be considered as sleepers. Many dealers and collectors are obtaining these gems as soon as they reach the market. Buying or collecting these stones can be extremely frustrating. Except for large chromes, they can be purchased for hundreds of dollars per carat. Many experts believe these stones will follow the path of tsavorite, and will soon be trading in the thousands of dollars per carat range.

Crysoberyl and alexandrite actually belong to the same gemological family. Known in antiquity as oculus solis, "eye of the sun", this gem's sharply reflected ray of light produces the spectacular effect of an iris of a cat. The two main components in the value of a cat's eye are color and the eye. The best color for a cat's eye is called milk and honey. The body color of the stone should resemble a pure golden honey. These stones typically come from Brazil. Most of the Sri Lankan gems tend to be greenish/yellow or greenish. These stones are available in all sorts of colors between the honey and the green colors. The eye, or the ray should be the color of milk, with possibly a bluish cast. The ray should be thin, bright, and obvious. All cat's eyes are cut in cabochon. If the stone is cut too flat, the eye will appear wide, wavy, and ill defined. If the stone is cut too high, the eye may be off center. Jewelry quality stones begin at $500 per carat. Fine cat's eyes can easily sell for $2000-$3000 per carat for 5-10 carat sizes stones. Exceptional large cat's-eyes can exceed $10,000 per carat.

Even rarer than alexandrite and cat's eye is the first green garnet, the demantoid garnet. This beautiful green gem was discovered in the Urals of Russia in 1886, and has not been mined until recently (See New Russian Demantoid Find). It derives its name from its diamond-like luster. Unlike most garnets, this gem looks like a green diamond. One interesting factor in demantoid garnets is that almost every Russian demantoid has a "horsetail" inclusion. This is one exception where an inclusion is actually a positive attribute. The stones tend to come bright green, with a yellow or blue secondary color. Most collectors do not purchase African demantoids.

George Kunz, on leave as buyer from Tiffany's, was financed by J.P. Morgan to buy all the demantoid he could find. The stone became the darling of the British and French aristocracy in the late 19th century. Many Victorian pieces of jewelry made between 1885 and 1915 possess demantoid garnets.

Demantoid tends to be found below a carat. A one carat demantoid is exceedingly rare. The largest specimen known to exist is only 8 carats.

Diamonds are the best known and most traded gemstone. Very few individuals collect white diamonds. One exception are individuals who collect D-Flawless diamonds. This is the ultimate "pure white ice" diamond. In 1974, you could buy one of these stones for about $5000. They topped out in 1980 at over $60,000 per carat. Today, you can buy a carat sized D-Flawless for about $18,000 to $20,000 per carat. Some people collect them in various shapes, such as rounds, pears, marquise, radiants, ovals, and princess cuts. Others just buy rounds. Also, some people collect only important large white diamonds. Collectors buy them for their history (perhaps someone famous owned the gem), or for their large size (any diamond over 10 carats is important).

The vast majority of collectors collect colored diamonds. No other jewel combines the rarity, beauty and sex appeal of a colored diamond. Let's face reality. The majority of white diamonds are not rare. The DeBeers cartel is the most successful cartel in existence. For over 60 years, they have convinced Americans that diamonds equate with love. On the other hand, colored diamonds are exceedingly rare, and are simply geological flukes. For every 100,000 D-flawless diamonds, there is probably one colored diamond, and it is probably not flawless. The beauty and the rarity of these gems has spawned unprecedented desire and unparalleled prices for these diamonds. If you are a collector, you can collect colored diamonds depending upon your financial resources. If you are in the highest economic circle, you can collect reds, pinks, greens, and blues. If you are moderate collector, you can own fancy yellows and oranges. If you are on a tight budget, you can specialize in browns, from cinnamon to coffee to light beige. One important fact to remember is that in colored diamonds, clarity is secondary to the intensity of the diamond's color.

Red is undoubtedly the rarest colored diamond. Besides the .95 red diamond sold at auction in 1987, only a few others are known to exist. In the 19th century, a famous London jeweler owned a carat-sized red, which he bought for 800 British pounds. Is this the same stone as the .95? In the 1920s a 5.05 emerald cut was cut from a 35 carat piece of rough. This stone was cut by the Goudvis brothers in Amsterdam, after being found in South Africa. Rumor has it that occasionally a red diamond is found in Borneo. Occasionally, a red diamond is discovered in Australia. Red diamonds are almost priceless. For more information on red diamonds.

Pink diamonds have always been exceedingly rare. In the 16th and 17th centuries, India was the principal source of pink diamonds. Recently, a famous light pink Agra diamond was sold at auction for almost $7 million. This stone was documented as being a gift to Babur, the first Mogul emperor, from the Rajah of Agra, for sparing his life in 1526. It later belonged to the Duke of Brunswick, the greatest connoisseur of colored diamonds of the 19th century. In 1725, Brazil produced some light pink diamonds. The Star of Brazil is a 128.80 carat rose colored gem, which was cut around 1832 in Amsterdam. An Indian gem collector paid 80,000 British pounds for it in the 1860s. It remains in India today. In 1947, Dr. John Williamson discovered a 23.60 pastel pink round diamond in Tanzania. It was not until 1979, when Australia discovered a small vein of pink diamonds that things really got exciting. Instead of being faint or light pink, these new diamonds are hot pink. They are producing about a 100 carats a year. The majority of gems are under one carat. In 1989, the Australian mine, Argyle, sold two pinks over 3 carats. It is rumored these stones were sold for $700,000 per carat. Expect to pay over $100,000 per carat for a fancy intense carat size pink. For more information on pink diamonds.

India was the main producer of blue diamonds from 1500-1700. This was the source for the 112.25 French Blue that later became the the infamous 45.52 Hope. Another famous blue, the 33.56 Wittelsbach showed up at a wedding in 1667, and ended up in Bavaria in 1717 with the ruling House of Bavaria, the Wittelsbachs. It is presently believed to be with a private collector in Germany. Today, new production of blues comes from South Africa or Australia. In order to understand pricing, here are some examples of recent auction prices. In October, 1994, at Sotheby's, a dealer representing a Hong Kong concern, paid $9 million, or over $460,000 per carat for a 20.17 blue diamond. In 1995, at Sotheby's, a 6.70 blue diamond sold for $3.52 million, or $525,000 per carat. The Apollo Blue, a 14.54 Fancy Vivid Blue, internally flawless sold for $42 million at Sotheby's or almost $2.9 million per carat in 2017. For more information on blue diamonds.

Besides the Hope diamond, the second most famous diamond is the Dresden Green. It is green and weighs 40.70. it is believed to have come from Brazil in 1725. It was purchased by Frederick Augustus the Second from a gem merchant at the Leipzig Fair in 1742. Since then, it has been exhibited for public display in the west wing of the Dresden castle. In 1983, a 8.19 rectangle green diamond was sold at Sotheby's for $396,000. In 1988, a 3.02 yellowish/green sold for $1.7 million. In 2008, a 10.36 square-shaped fancy green diamond fetched $3.4 million or $336,417 per carat at Christie's. For more information on green diamonds.

Although faint yellow in white diamonds is not desirable, fancy intense yellow is sought after. Although India produced some yellows in the 16th and 17th centuries, South Africa today is the main producer of these gems. As a matter of fact, the first authenticated diamond found in South Africa was the 10.73 yellow Eureka. By 1900, South Africa had produced the 128.51 Tiffany, the 130 carat Colenso, the 228.50 DeBeers,and the 205.07 Red Cross. In 1996 at Christie's, a 8.45 fancy vivid yellow sold for $684,500 or $81,000 per carat.

Today, collectors can buy yellows in various shades from lemon yellow to taxicab yellow. The best pure yellow or orangish yellow will be called "fancy intense" or "fancy vivid" yellow on the Gemological Institute of America (GIA) grading report. These diamonds are rare and expensive. Slightly below these stones are the fancy yellows. These stones are more affordable but still quite yellow. For more information on yellow diamonds.

In an ideal perfect world, you should try to collect orange diamonds that look like a Halloween pumpkin. These pure diamonds sell for more than the yellows. A 8.93 fancy intense orange sold for about $1.9 million at Sotheby's. However, if you are looking for a bargain, focus on oranges with yellowish secondary colors. You can also collect intense oranges with just a hint of brown at substantially reduced prices. For more information on orange diamonds.

If you want to speculate on a fancy diamond at affordable prices, browns are a natural choice. The connoisseurship of brown diamonds may be in its infancy. In essence, these are the only colored diamond bargains left. Cardinal Jules Mazarin, the chief minister of France in the 1600s collected brown diamonds. In 1967, a 115.59 African brown pear shape was discovered. It was reportedly sold in 1983 for $900,000. You can buy coffee colored diamonds for $2000+ per carat. This is lower than many white diamonds.

Collectors are fascinated with emerald. This rare and exotic gem is also known as "green fire". Colombia is the main source of gem emerald. This South American country is one of the most dangerous and unstable places in the world. Many visitors recall the similarities between Chicago in the 1920s and Colombia today. With the highest murder and kidnapping rates in the world, cocaine cartels and a long-running guerrilla insurgency, Colombia is often referred to as "Locombia", or the mad country.

The two most famous mining areas are Muzo and Chivor. Muzo is located 100 kilometers north of Bogota. The district is hot and humid, and it constantly rains. Muzo and Cosquez are the major mines here. Emeralds are found in black calcium-rich shale. Most of the stones from these mines are horribly included. Chivor, which is northeast of Bogota, is in a rugged, almost inaccessible topography with thick, forest vegetation. The two major mines of this district are Chivor and Gachala. Chivor mine sits 2300 meters above sea level on a mountainside. Chivor was originally mined by the Chibcha Indians and emerald was traded from the Andes to Mexico until the mine was lost. Chivor was rediscovered in 1896. In this area the rock is black shale and sandstone. The Colombian emerald market is wide open. Although the Colombian government leases mining rights to private business, illegal mining is the rule, not the exception. No one even pretends to control the situation.

Which mine is better for collectors? The terms Muzo and Chivor are often used in the trade, not so much to determine the exact source of a gem, but rather to to describe the qualities of the emerald. "Muzo" is used to describe a warm, grass-green emerald, with yellow being the secondary color. "Chivor" stones are like the pine trees of Washington state, with blue being the secondary color. Certain collectors and dealers argue about which color is the best, but it is really a matter of personal preference. In top colors (3.5 to 4.5 AGL) , both types of these emeralds are highly desirable and expensive.

Emeralds are very included compared to most gemstones. Inclusions that would not be acceptable in ruby and sapphire are acceptable in emerald. The definitive identifier for Colombian emerald is the three-phase inclusion; solid, liquid, and gas. Even though the gem is typically mined with eye-visible inclusions (even at the collector level), emerald is the most popular colored gem in America. Probably 98% of all emerald discovered would be graded Heavily Included (HI) or worse at the AGL. Therefore, a Moderately Included 2 (MI2 from the AGL) is considered a relatively clean emerald.

Most collectors seek strictly Colombian emeralds. They spend decades buying the finest green and cleanest stones available. Occasionally, African and Brazilian emeralds are discovered that look exactly like Colombian emerald. These gems make sense to collect if you are an emerald connoisseur. If you have a moderate budget, you can purchase African emerald. As a general rule these gems are cleaner than Colombian emeralds but have a touch of black and gray colors. They trade at a 50% discount to Colombian stones. Finally, if you are on a limited budget, occasionally Brazil produces nice stones at about 1/2 the price of Colombians. As a general rule, Brazilian emeralds are green/black in appearance.

Commercial quality Colombian emeralds can easily range from $500-$2500 per carat for one carat stones. High jewelry quality ranges from $2500-$5000 per carat. Gem, one carat emeralds range between $5000-$10,000 per carat. The finest color, four carat or larger Colombian emeralds can easily fetch $20,000 per carat. A ten carat, gem emerald can exceed $50,000 per carat. If an emerald is AGL graded as No Clarity Enhancement, add 100% to these figures. Many collectors search for untreated emeralds only

Approximately 99% of all emeralds are treated. Similar to the heating of ruby and sapphire, this is perfectly acceptable. Emeralds have been oiled for centuries. Treatment is only possible when inclusions break the surface. Clear oil is forced into surface-breaking inclusions, thereby reducing the visibility of inclusions. Oiled stones tend to fluoresce a pale yellow. Some collectors view this process as akin to buying fine furniture. Once a year it is brought into the manufacturer for a re-oiling. A new treatment for emeralds is opticon. Some dealers contend opticoned emeralds have a better finish, are more durable, and the treatment is permanent. Opticoning uses the same theory as oil, but inclusions are filled with a thick epoxy instead of oil. The stones are sealed with a thin coat. A brand new treatment was introduced in 1997 named Gematrat. They state that their filler "de-emphasizes" the visibility of fractures but does not hide them. Suffice to say, if you collect emeralds, you should be aware they are probably treated in some fashion. Demand an AGL report if the stone is in question.

For updated information on emeralds.

(This section updated January, 2002)
Although most people tend to think of sapphire as being blue, it actually comes in a kaleidoscope of colors. Besides blue, their hues can be orange-pink (padparadscha), pink, orange, yellow, golden, purple, green, white and color change. Of course, corundum that is red is ruby, when it is discovered any other color it is sapphire. The major sources for fancy colored sapphires are Burma, Madagascar, Sri Lanka, Thailand, Australia, East Africa, and even the United States.

With a hardness of 9, sapphires are extremely tough and durable and suitable for use in any kind of jewelry. It is the hardest gemstone type known except diamond. All corundum is a common natural mineral, aluminum oxide. What is rare are the small trace elements of titanium, iron, chromium and vanadium which create the various colors in fancy sapphires.

The rarest and most valuable collector fancy sapphire is the padparadscha, which is Sinhalese for "lotus flower". A true padparadscha must display a combination of both orange and pink colors. These colors should blend so that it is difficult to see where the pink stops and the orange begins. Dealers disagree on the exact ideal color of a padparadscha. Tone and origin are crucial factors in determining what truly constitutes this gem. We believe the term should be limited to the light to medium tones of Sri Lankan (Ceylon) sapphires with a color that is similar to salmon. In our opinion, the Umba Valley, Tanzania gems and the new Madagascar material do not have the same attractive color in the classic sense. Some unscrupulous dealers have been selling African fancy sapphires as padparadscha. However, these stones have too much orange-brown to be properly labeled "pads". Sri Lankan padparadscha sapphires sell at a premium, nearing the price of a Kashmir sapphire. An unheated gem padparadscha will range between $5000-$16,000 per carat. Large gems can exceed these prices. Padparadschas are hot collector items and are bought up as quickly as they are found.
The second most valuable fancy sapphire is "electric" or "bubble gum" pink. The best of these gems have a pure vibrant and vivid pink color. What makes these stones exceptional is an electric intensity and a tone that pushes them way above a pastel color. Dealers, gem organizations, labs and collectors argue about where to draw the line between ruby and pink sapphire. One problem with grading these stones is the color pink is basically a light or desaturated red. On the AGL grading system, there is a transition point for pink sapphire/ruby. If the stone is redder than this point, it is called a ruby. If the stone is less red, it is a pink sapphire. And, although these gems are technically pink sapphires in America, some cultures, such as the Japanese and Europeans, refer to this color as "Burma ruby". This makes it very difficult for US collectors. The main sources of these gems are Burma, Sri Lanka, and Madagascar. The supply of Sri Lankan and Burma goods remains scarce. Most of the heated pinks on the market today are from Madagascar and sell from $200-$1000 per carat. Unheated gem Burma pinks sell from $1500-$3500 per carat. Large multi-carat sized Burma pinks can exceed $7000 per carat. Many collectors consider "hot" pink sapphire as an inexpensive alternative to the red Classic Mogok Burma ruby.
Yellow, Golden and Orange
Yellow, golden and orange sapphires are interesting gems for collectors on a moderate budget. These gems are still relatively unknown by "the public". Many believe that once they receive more exposure, they will be a favorite among privates.

One caveat with yellow, golden and orange sapphire though, is the gems can be subjected to numerous treatments. It has been estimated over 90-95% of the world's sapphires in the market today are heat-treated. The theory of heating yellow sapphire is to add value by improving color and often clarity. Pale yellow stones have been heated consistently for over twenty years by Thai cookers and others. In the early 1980's, the yellow sapphire market crashed when large supplies of treated product entered the market at the Tucson Gem Show. During the past twenty years, the supply/demand balance has reached a better equilibrium.

Proper heat treatment of pale yellow sapphire may produce intense yellow, yellow/golden, golden and deep orangy yellow colors. Interestingly, in the last few months, a certain type of brownish-red (garnet-looking) Tanzanian corundum from Songea, Umba and elsewhere has been heat-treated in Thailand, often resulting in beautiful orange, yellow/orange and other colors. Most natural pale yellow sapphires are heated between 1600 to 1900 degrees centigrade to produce more attractive shades, but heating yellow sapphires does not always work and often the material may turn colorless or pastel. According to Ted Themelis, author of The Heat Treatment of Rubies & Sapphires, "The results after the treatment vary widely depending upon the ratio/type of the gems' color-bearing impurities, the heat-treatment method applied, and the various parameters used in the heating process." Heat treatment on most yellow sapphires is permanent and requires no special attention by consumers/jewelers after the sale.

A great deal of yellow, golden and orange sapphire is irradiated. This treatment is used on pale yellow sapphire to turn it golden yellow. Some light blue sapphire also turns orange after irradiation. This process is not stable and the color produced by this method can fade in light or heat. This is not acceptable. Irradiation is detected by conducting a fade test. The test is accomplished by masking off 50% of the stone and placing it in the sun for a few days. The tape is then removed and the gem inspected to see if both sides have retained the same color. If the color of the exposed half of the gemstone has faded, it has been irradiated. It is impossible to detect whether a gem's irradiation is man-made or natural. Natural irradiation occurs when a gem is exposed to the earth's radiation while still in the ground, similar to what causes the green coloring of diamonds. Sapphire can also come "chemical-coated" and with "surface color diffusion".

Fancy yellow sapphires occur in a myriad of shades. These stones can look canary-yellow-diamond bright, vibrant golden and electric orangy yellow. Interestingly, collectors search for the paler, unheated yellows over the more intensely hued treated gemstones. These stones are an exception to the general rule that the better the color, the more valuable the stone. Collectors will choose a natural untreated yellow sapphire over an irradiated or heated vividly colored gem. However, unheated yellows should not be too pastel, they must be obviously yellow or lemon yellow. If you have to use your imagination, pass on the stone. Occasionally an untreated yellow sapphire also can also possess an intense, extremely deep yellow color. The best yellow sapphires possess a light to medium tone, without any brownish overtones. Finally, the cleaner the stone, the more valuable the gem. However, be careful, because in some cases flawless yellow sapphires are treated synthetics.

Top quality unheated Burma yellow sapphire is available for $1800-$2200 per carat in two to four carat ranges. Ten carat sized stones can exceed $3500 per carat. Cut these prices in half for Sri Lankan, Australian, or Thai stones.

Yellow sapphire provides an inexpensive alternative to consumers who cannot afford a fancy yellow diamond. The stone comes in colors from fancy light to fancy deep yellow. They can be purchased for hundreds of dollars per carat vs. thousands or tens of thousands of dollars per carat for yellow diamonds. Today, yellows are hot in the astrological gemstone market and rare, untreated yellows are sought in the collector market.

Sapphires are also discovered purple. Some exceptional purples are found in Africa and Burma. They are often described as intense electric purple or plum color. Watch out for purples with gray or brown. Exceptional one carat purples range from $1000-$1500 per carat. Two to five carats can reach $2000-$4000 per carat. Large purples can exceed $4500 per carat.
Color Change
A new supply of unheated, fancy color change (purple to blue) Burma sapphire has recently entered the market. In the best cases, these goods are beautiful with a deep color saturation and an obvious color change. Most of the world's fabulous color change sapphires come from the Umba River region of Tanzania, the famous Mogok stone tract in Burma, and the Ratnapura area of Sri Lanka. The color change Burma sapphires we have seen recently fluoresce strong red in LW (Long Wave) ultraviolet light. This is due to a minor degree of chromium in the material.

Sapphire is one of a few gemstones that can exhibit a color change. A color change gem is a stone that changes from one color to another color depending upon the light source. Color change sapphires go from blue in daylight to purple or violet in incandescent light. The color change occurs in sapphire because of the atomic structure of the stone. The ultraviolet rays in sunlight or fluorescent light excite the atoms in a color change, but artificial (incandescent) light does not. As a general rule when evaluating color change gemstones, the more dramatic the color change, the more desirable the material. You do not want to use your imagination to see the color change. Ideally, you are looking for a 100% color change with two pleasing colors. In sapphires, one side should look like a gem blue sapphire and the other side a top quality amethyst. You do not want a stone that "bleeds", which means you can see the two colors at the same time under a single light source. Additionally, the more vivid the color of a color change, the more valuable the gemstone is. Generally, sapphires with a pastel color (lighter tone) exhibit a less dramatic color change. Color changes can also be too dark (black out) and the color change is masked by the black. Ideally, you want a dramatic color change with a medium tone and intense color.

Today, one to three carat size, top gem quality, unheated Burma color change sapphires range wholesale from $1500-$3000 per carat. Three to five carat sizes are $2875-$3400 per carat and large color changes can reach $6000 per carat. Color change sapphires over 10 carats are extremely rare.

Color change sapphire is also known as alexandrite-like sapphire. However, many may prefer the dramatic color change of top sapphires over the meager supply of weak color change alexandrite presently on the market. In addition, while top alexandrites can reach over $20,000 per carat, top color change sapphires are available for approximately 1/3 of the price.

Green sapphire is a relatively abundant stone from Australia and Thailand. The problem is they usually exhibit black/gray secondary colors which dramatically reduce their value. Some new African production that is a more pure green has recently entered the market. Some greenish blue stones are sometimes found in Burma. Top gems can sell for $1000 per carat and larger 5-10 caraters can reach $1500-$2000 per carat.
Finally, some sapphire occurs white. For years this stone sold for $10 per carat. Then the Thai cookers realized that some white sapphire turns vibrant orange after heating. In addition, white sapphires are treated with a diffusion process to turn blue. This has increased demand for these gems and put upward pressure on their price. White sapphire now trades between $900-$1700 per carat.

You must assume that all sapphires, unless otherwise confirmed by an American Gemological Laboratory (AGL) Colored Stone Grading Report, are heat treated. To help identify an unheated Burma fancy sapphire, try to locate short rutile needles that intersect at 60 degree angles and inclusions that are intact (unexploded). Although the heating of sapphires is acceptable in the trade because the process is permanent, it must be disclosed to consumers. Without this treatment process, it would be impossible to meet the world demand for fancy sapphires. Some dealers claim their fancy sapphires are cooked with" low" heat. This is like being a little bit pregnant, a gemstone is either heated or not, although low heat is preferable to the "super-fried" treatments of today. Another relatively unknown treatment issue for sapphires is oiling. The oil can be removed by soaking the gemstones in acetone or similar chemicals. An accurate view of the material is possible after the process is completed. Once the oil is removed from the sapphires the material can then be safely cleaned in ultrasonics and steamers. Due to the potential treatment issues of heat, oiling, and irradiation, it is important to have an independent lab report when buying/selling an expensive fancy colored sapphire.

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