Pezzottaite: The Lost Cousin of Beryl



When the world discovered red beryl – also known as bixbite – in 1903, mineralogists across the world searched for more deposits of the rare reddish pink gem without much luck. But in 2002, a deposit of pink stones were discovered in Central Madagascar to the delight of many enthusiasts as red beryl deposits are exhausted. With high hopes of finding a new source of red beryl, the initial stones from this these mines were marketed as red beryl. But upon closer inspection, mineralogists realized that the raspberry hued stones were not red beryl, nor part of the beryl family at all; these were a new gem – pezzottaite.

Recognized by the International Mineralogical Association as a new gemstone in 2003, pezzottaite is named after Italian mineralogist Federico Pezzotta. Although similar to beryl family of gemstones in appearance, pezzottaite contains lithium and cesium not found in beryl. In addition, pezzottaite is a trigonal crystal system while beryl is a hexagonal crystal system. Pezzottaite can also form chatoyancy cabochons, or cat’s eye.

The color hues of this gem can range from orange-red to pink to raspberry red (purplish-pink). The raspberry color is what pezzottaite is famous for; hence, the other various names like raspberyl and raspberry beryl. Like morganite and red beryl, the color comes from manganese within the crystal structure. Pezzottaite also has a much higher refractive index – the ability to bend light – which makes this stone more lusterful than beryl.

Being such a new gemstone, there is a limited supply of pezzottaite in the world. As such, it is mainly a collector’s gem at the moment due to scarcity. Still, many are attracted to the pink hue despite its rarity. Because of the low supply, it is very rare to find a good faceted pezzottaite over one carat; finding a clean stone might be just as hard. For comparison, the largest good quality faceted pezzottaite is only 11.31 carats while the largest diamond is 317.4 carats – the Cullinan. 17.36 carats is the largest cabochon with cat’s eye.



Having the Mohs hardness of 8, similar to beryl, pezzottaite is suited for most types of jewelry but still a brittle stone so care must be taken. However, the lack of supply means that the stone might be hard to get your hands on, must less finding a home in a piece of jewelry. Still, pezzottaite is less valuable than red beryl but more expensive than morganite. Pezzottaite and red beryl are often mistaken for each other so certification is a must if you’re looking to avoid getting the wrong stone.

Another attribute to look out for when dealing with pezzottaite is that the stone does lose its color when heated to 450°C for two hours. Meaning that heat treatment have a negative effect on the color hue of this gem, unlike many other gemstones, where heat enhances the color. However, gamma irradiation does restore the color loss due to heat treatment. Other words, vivid pezzottaite gems are most likely natural.

Unfortunately, the original mine in Ambatovita, Madagascar where pezzottaite was discovered has been exhausted to our knowledge. Fortunately, there are some deposits in Afghanistan and Burma that have popped up in recently to continue supplying the world with this rare beautiful gem. Until a large deposit is found, grab these while they last.

Benitoite: The California Sapphire



With a rich, deep sapphire blue and the luster of a diamond, the appearance of benitoite to the gem world has excited both collectors and scientists. Why are scientists interest in this gemstone? Well, benitoite – a hexagonal class that forms flattened triangular crystals – is the first discovered mineral to crystallize into a ditrigonal dipyramidal crystal system, called “Benitoite type;” mathematically proposed but never found in nature previously. Because of its special crystal system, benitoite can form a six sided star similar to the Star of David.

Discovered in 1906 by James Couch in San Benito, California – where its name comes from. The blue stone was originally thought to be sapphire but later identified as a new specimen in 1907 in UC Berkeley. In addition to being discovered and identified in California, benitoite became the official gemstone of California in 1985. Gem quality stones are still only found in California.

Benitoite, BaTiSi309, get its color from barium and titanium. Researchers think the deep blue comes from traces of iron in the crystal matrix while titanium gives the stone a violet blue tone. Benitoite can come in colorless, pale pink, greenish, gray, violet, and blue. But, its rich sapphire blue with a hint of violet is what makes this gemstone popular, similar to the rare tanzanite.

Unfortunately, there are few naturally blue samples as most are greenish-gray. The good news, blue benitoite is not affected by heat treatment so any blue benitoite gems are likely natural. Colorless stones can be treated with heat to produce orange tones. There are red to maroon stones, as well, due to inclusions of neptunite, which is commonly found with benitoite.



Having one of the rarest crystal form, benitoite is also has dichroic properties, different colors at different angles, like tanzanite and tourmaline. Besides able to form a six sided star in nature, benitoite potentially has a higher refractive index than diamond; making good clean and cut stones greater internal fire and brilliance than diamond. Because of these properties, benitoite is sometimes called, “blue diamond.”

Due to it’s rarity and uniqueness, this scared gemstone can command $3,500 to $5,000 for a cut one carat with good clarity and color; $10,000 per carat for those over two carats. Uncut stones in a good mineral matrix – neptunite and natrolite – can still cost thousands of dollars. Clusters of blue benitoite and black neptunite on white natrolite are very rare and highly sought after by collectors since good sized cut stones are so rare.

With only a Mohs rating between 6 to 6.5, benitoite is not suitable on jewelries that can expose the stone to hard impacts. So rings are not recommended but wear them if you desire. Pendants, earrings, and necklaces are spectacular.

Besides being such a luster gem, high quality benitoite stones are used to align and adjust electron microprobe beams. As such, demand for this gemstone is high. Unfortunately, the California mines in the Diablo Mountain Range, where benitoite was discovered, are depleted. There are deposits in Japan, Australia, and other parts of the United States – Dallas and Arkansas – but none of them so far produce any stones of good quality. Making benitoite rarer than tanzanite but a treasure to those lucky enough to have one in their collection.

Bixbite: Red Emerald of the Beryl


Deep within the beryl family, lies an elusive member, that is more rare than morganite – covered previously. This relatively unknown gem, one of the rarest in the world, goes by many names over the years – like red beryl and red emerald – but the original name is bixbite; red beryl is the current accepted name to avoid confusion with bixbyite, a little more on that later.

Discovered in 1904 at Thomas Mountain – also known as Topaz Mountain – in Western Utah by Maynard Bixby, who also has a different rare black mineral named after him called bixbyite, hence red beryl is commonly used to distinguish the two. Unfortunately, the initial deposit of bixbite was very small and not of gem quality. Another deposit was not found until 1958 at the Ruby Violet Mine in the Wah Wah Mountains, Southern Utah. This deposit did provide gem quality bixbites and, currently, the only source of this sparse gemstone, thus making bixbite one of the rarest gemstones in the world.



Marketed as “red emerald” in 1998, bixbite has the same basic composition – beryllium aluminum cyclosilicate – as other beryl gemstones except there are impurities of manganese in the crystal matrix, similar to morganite. Since pure beryl is colorless, this impurity gives the stone its color that can range from rose, orange-red, raspberry to dark red. The most prized color is a rich red called “stoplight.”

Due to the rarity of this stone, most bixbites are less than one carat while any between two and three carats are considered very large samples. The usual facted size is only 0.15 carat, with the largest faceted bixbite being 8 carats and the largest crystal stone being 54 carats. A fine quality faceted, cleaned bixbite with a stoplight color can command about $10,000 per carat.

Mentioning clarity, most colored stones will have some inclusions in them, even if tiny. As such, “cleaned” to a colored gemstone is determined by being clear to the naked eye. One should be careful with inclusions on the surface as dye and glass can be injected into the cracks to make the gem darker in color. Obtaining a certificate or buying from a reputable merchant is always a good idea for any rare precious stone but making sure your bixbite is natural and unaltered is especially important.

Bixbite crystal, hexagonal structure

Once said that only one woman in two million would ever own this precious gemstone, which is a pity because this beautiful crimson stone has a hardness of 7.5 Mohs makes for a good gem for everyday use jewelry. Yes, ruby jewelries would be more affordable, but attraction to red beryl is owning something rare for the collector inside of us.

Potential buyers should also be aware that some red beryls on the market are actually pezzottaite, another rare gemstone discovered in Madagascar in 2003. Pezzottaite is not in the same beryl family as it has a different crystal structure and contains lithium. Although valuable in its own right, pezzottaite is not valuable as bixbite. In addition to mislabeling, you should watch for lab synthetics if you’re interested in the real thing. Again, when dealing with such a rarity of a gem like bixbite, certification and reputable dealers go a long way.

Morganite: A Banker’s Pink Gemstone


In the gleaming shadow of emerald and aquamarine, lays a pink gemstone that radiates delicacy and glamour; the gemstone in question is morganite. A light pink to violet-pink variety of beryl, the same family as the mentioned aquamarine and emerald, morganite was once simply called pink beryl – even called pink emerald at times – before it was officially given a name. Despite being the one of the rarest variety of beryl, second only to bixbite, this pink gemstone is the most sought after pink stone in recent years.

One of the new wave of “new” gemstones discovered within the century, morganite was discovered in 1910, in California, by George D. Kunz, the very same that has kunzite named after him, and suggested that morganite be separated from beryl in naming. The pink morganite stone is named after the J.P. Morgan – the billionaire banker and, concidently, biggest customer of Tiffany & Co., who Kunz was also working for.

pink_morganite
Loose pink morganite

The color of this stone comes from manganese or cesium impurities in the crystal matrix. Impurities in the beryl turns the colorless stone into a pale or pastel pink hued stone; intense or vivid colors are rare for this gemstone. As with many colored precious stones, usually the larger the stone, the deeper the color will be; smaller sized morganites are paler in color.

As such, the radiate pink hues are what make this magnificent gemstone so special; pure pink and magenta being the most popular colors. Even so, many may prefer the pale shades. Also, in recent years, peach and salmon morganites are gaining popularity among buyers. Pick the size and shade that calls to you.



Speaking of color of this lust stone, you should know that many morganites are indeed treated with heat in today’s market to improve the color and reduce yellowish tints in the stone. Heated at relatively low heat of 400°C – relative as some gemstones like sapphires are treated at 1600°C – the treatment creates an improved color shade that is stable and will not fade over time; reasons why heat treatment is so common.

Having a Mohs of 7.5 to 8, morganite makes a good everyday jewelry with good hardness, durability, luster, and radiance. Rings, pendants, earrings, necklaces, and bracelets are all great choices for this stone. Morganite can form chatoyancy, or cat’s eye, pattern that are usually polished into a cabochon, then mounted into pendants. In addition, morganites can also exhibit asterism, or star, pattern as well.

Although “discovered” in California, and still mined there, morganites of high quality are mined from Brazil and Madagascar. Other important deposits of fine quality are Afghanistan, China, Mozambique, Russia, Zimbabwe, and the United States – California and Maine.

With such a beautiful, soft pink color, one can easily see why morganite can be an enchanting gem to so many around the world. Best of all, this is a very affordable gemstone, even though it’s rare compared to more established gemstones. With that said, you might have a problem getting your hands on this gemstone in retail stores, which can be unfortunate, but morganites can easily be obtained on online stores.

How to buy Kunzite & Hiddenite Guide


Kunzite and hiddenite, the two varieties of spodumene, are relatively “young” in the gemstone world. Both stones are quite rare in the market today as there hasn’t been enough time to accumulate supplies like the “older” gemstones. Nevertheless, these gems are delicate and beautiful that attract many that come across them. As such, this is a quick guide on how to buy these lovely gemstones for first and seasoned buyers.

Kunzite

Color – kunzite usually appears in various shades of pink – due to the impurities of manganese – but they do occur as lavender, violet, and purple; however, pink is the defining color of kunzite. Deep pink kunzites are considered the most valuable.

Having pleochroic properties, a single stone can have different shades and hues of pink, even colorless can be observed, depending the the viewing angle and light source. Because of this, you should rotate the stone in your fingers whenever possible. Some kunzites will have two good shades of pink; the most desirable color is usually seen from the top of the gemstone.



Cut – the second most important factor in the valuation of a kunzite gem since this will determine how beautiful the gemstone will be. The characteristics of perfect cleavage, splintery fracture, and pleochroism make kunzite is a difficult stone to cut that usually tackled by expert cutters only.

Cutters have to avoid breaking the stone while finding the best angle to maximize the color of the stone; as stated earlier, cutters will try to get the deepest pink to display from the top of the gem. Kunzites under two carats are rare as they are not worth the effort.

Clarity – kunzites are not a clean stone, like other colored transparent gemstones, so slight inclusions are common; a perfectly clear kunzite is very rare as the standard is eye-clean. Obviously, the more flawless a kunzite is, the more valuable the gem becomes.

Carat – this enchanting gemstone’s dark color and pleochroic properties are best observed in larger sizes. 10 carats is the ideal size with beautiful color and pleochroic plays of color. Kunzites in the 2 to 6 carats range are commonly used in jewelries. Sizes of less than two carats are rarely seen in the market.

Price – an affordable gemstone, kunzite follows many of the same rules of gemstone valuation using the four C’s; color, carat, cut, and clarity. Stones with deep pink command a much higher price than lighter shades of pink. Violet and purple colored kunzites can fetch a moderate price. In addition, treated or enhanced gemstones are less valuable, obviously.

Hiddenite

Color – hiddenite can appear in various shades and hues of green. The colors can range from near colorless light green to yellow-green to dark emerald green. The green color comes from impurities of chromium oxide, the same compound that makes green glass, in the crystal structure. Deep green, similar to emerald, is considered the most valuable color to obtain.

Hiddenite also displays pleochroism. This characteristic lets hiddenite the ability to have to a few different shades of green on the same stone. Rotating the stone with your fingers will bring out the various different shades of green, but most cutters will try to showcase the deepest green on top of the stone.



Cut – as mentioned above, hiddenite is a difficult stone to properly cut that only expert cutters will dare attempt. This gem’s perfect cleavage, which makes the gemstone vulnerable to breakage, combined with splintery fracture and strong pleochroism can make this gemstone a nightmare to inexperienced cutters. Cabochons are common when the cutter does not want to risk damaging the stone. As such, expertly faceted hiddenites are rare and highly sought after.

Clarity – hiddenites are transparent gemstones with a glassy luster. Unlike diamonds, flawless inclusion-free hiddenites do not really exist; fine quality hiddenites are eye-clean, no visible inclusions.

Carat – as with kunzite, hiddenite is at its best at 10 carats and above. This is due to the fact that thicker crystal matrix gives the stone a deeper, beautiful color and enhanced pleochroic play of colors. Many cutters will not bother cutting stones under 2 carats.

Price – on average, the price of hiddenite is about $100 per carat, making them an affordable alternative to emerald; although a good colored 5-carat hiddenite can cost about $400 per carat. Being viewed as an alternative to emerald, the most valuable stones are ones with intense, deep green that resemble an emerald. A fine cut 1-carat hiddenite ring can cost about $1000.

Hiddenite & Kunzite: Twins of the Spodumene


There are gemstones that everyone knows by name – emerald and ruby – but there are much recently discovered ones that are just as beautiful and cheaper than the established old guards. Two of these stones are hiddenite and kunzite, both a variety of spodumene, twin gemstones that sparkle and dazzle like the best of them.

Hiddenite
Hiddenite was discovered in North Carolina in 1879 by William Earl Hidden while inspecting an emerald mine. Like emerald where it was found next to, hiddenite is a transparent green gemstone that can range from yellow-green to dark, emerald green.



The green color comes from the impurity of chromium oxide in the crystal matrix; chromium oxide is what is added to glass to make it glass. The lack of chromium oxide makes the stone appears more yellow. The most valuable hiddenite gemstones have uniform, deep green color with good clarity. These top notch specimens are highly sought after by collectors and museums.

Speaking of uniform, this gemstone does have pleochroism, meaning that it will display a few range of colors – like yellow, green, and light brown – at different angles. This property, combined with its perfect cleavage – or tendency to break along flat planar surfaces, makes hiddenite a difficult stone to cut with uniform color.

Because is such a difficult stone to cut, high quality faceted hiddenite gems are very rare. In addition, hiddenite – having a Mohs rating of 6.5 to 7 – is susceptible to hard knocks that will chip it. Most hiddenite jewelries are either earrings or pendants to protect the gem from being accidentally struck but, of course, choice a piece that you like. Hiddenite jewelry should also be kept in jewelry box or case as extended sunlight or bright light will fade the luster gemstone.

Hiddenites from North Carolina are very rare these days. Today, the major deposits are in Afghanistan, Brazil, Madagascar, and Myanmar.

Kunzite
Kunzite, the rare twin of hiddenite, was first discovered in Connecticut, USA; but the first commercial deposit was found in San Diego, California in 1902 by George Frederick Kunz, who first cataloged it. Similar to amethyst, kunzite can range from light pink to violet.



The traces of manganese in the crystal matrix is what gives kunzite its pink-purple color. The stronger the color, the more valuable the stone becomes, mainly because strong colors are rare. Color intensity is even more valued than clarity. Kunzite is also often found with other pink stones like morganite and pink tourmaline.

Like its twin, kunzite is highly pleochroic. A single gem can be pink, purple, and even colorless depending on the viewing angle. This property makes this gemstone an interesting addition to collections but a nightmare for cutters.

As a jewelry, kunzite has the same properties of hiddenite and should be kept away from sunlight and bright light for extended periods of time due to fading of its brilliant color. Extended heat exposure should be avoided as well. Wearing them to the beach and sunbathing is not recommended. Kunzite pendants and earrings are popular choices for this stone but don’t limit yourself if you want a nice kunzite ring.

Much of the appeal of this brilliant gemstone is its delicate pink color with hints of violet due to the pleochroic property it shares with hiddenite. One of the best property of kunzite – and hiddenite – stones are their affordable prices at large sizes. The Smithsonian, for example, has a faceted 880 ct. heart shaped kunzite.

Kunzite is mainly mined in Afghanistan, Madagascar, and Brazil. Afghanistan generally produces strong violet and light violet kunzites with hints of light green at different angles. These can be a marvel to behold in your hands. A great gemstone for lovers due to its seductive and tender hues.

How to Buy Alexandrite


Although being a variety of chrysoberyl, a fairly affordable stone, alexandrite gemstone is one of the most expensive gemstone in the world. The fetching price is in part due to its ability to change color, from blue-green to purple-red, and rarity.

The original deposits in Russia, the only source known at the time, have been exhausted and most of those Russian alexandrites are now in private collections or museums; making this gem extremely rare and valuable – a good investment gemstone. Luckily, another quality deposit was discovered in Brazil in 1987 to supply the world with more of this fascinating gemstone. However, there are some differences, Russian stones have a nicer green in daylight, while Brazilian stones have better shades of red.

Like many colored gemstones, the grading for alexandrite is a bit different compared to diamond, where color is more emphasized than clarity. Of course, as with any valuable gemstone, obtain a Certificate of Authenticity or Gem Identification report wherever possible. With that, here’s a quick guide on how to buy alexandrites.



Color
The quality of color of an alexandrite stone is most important factor in depending the value of the stone, especially the color change, since this factor is what makes this stone different from every other precious stones.

Although no such stone has yet to be found, the ideal is an alexandrite that changes from green to red; 99.9% of all known alexandrites do not display perfect green to red color change. Top examples go from blue-green to purple-red; think emerald during daylight to amethyst while in artificial light. Brown and gray colors in the gemstone will lower the price.

To further distinguish from other gems, alexandrite has a percentage rating system by the American Gem Lab for color change; with 100% being the unreachable ideal and stones with 30% or less are considered uninteresting – and not even an alexandrite. Stones with at least 90% color shift is considered as fine, top quality. As a caution, however, use the AGL system as a reference as there’s currently no set standards between labs around the world.

If you can get your hands on the gem, make sure to examine it under different artificial lights, intensity and angles as the red color will show better when the artificial light source is pointed across the gem instead of directly upon it.

Check color temperatures to make sure they’re at the optimal range for good color. 3000k to 3300k is good for incandescent, or artificial, light and 5000k to 6500k is good for daylight. Flashlight or penlight can be used as an incandescent light.

Clarity
Like many colored gems, like ruby, it is normal for alexandrites to have some inclusions – foreign particles, fissures or bubbles – and be graded without magnification. As such, the highest classification it can receive is a VVS, very very slightly inclusions. Adding the fact of its rarity, clean stones up to one carat is rare and ones over a carat is extremely rare.

Carat Size
Because of the rarity of these gemstones, quality faceted alexandrite over two carats are rare, even quality faceted ones under 0.5 carat can be worth thousands of dollars per carat. Anything above five carats are extremely rare. With that said, Sri Lanka does produce alexandrite stones over 10 carats, but many of these do not display satisfying color change.



Source
As stated earlier, Russia – the sole producer for decades – is no longer producing anymore of these alluring gemstones; a true shame as Russian alexandrites are still the standard today. Currently, these stones are mined all over the world including Sri Lanka, Burma, India, Tanzania, Zimbabwe, and Brazil. India is the main of source of alexandrite gemstones in the world today.

Since the deposits in Russia dried up, the Brazilian deposits brought excitement back to many enthusiasts with good color change and strong colors comparable to their Russian counterpart. Unfortunately, this deposit is also exhausted. In the 1990’s, deposits in southern Tanzania were discovered to produce fine quality of alexandrite stones as some world class specimens have came from this region.

Price
Quality alexandrites with good color change can demand prices that exceed gemstones like sapphires, emeralds, rubies, and diamonds. Verified stones from Russia are the most valuable with Brazilian ones being a distant second. For example, an one-carat top quality stone from Russia with great color change can cost up to $15,000.

Natural alexandrites with about 90% to 100% color change – considered top quality – under 0.5 carat can cost $2,500 to $5,000, while gems between 0.5 to 1 carat can cost $5,000 to $15,000, and those above 1 carat are up to $1,000,000/ct.

Those with 70% to 89% color change that are under 0.5 carat cost $1,500 to $5,000, with alexandrites between 0.5 to 1 carat demand about $3,000 to $9,000, and stones above 1 carat are valued up to $60,000/ct.

Stones with slight red-green color change, 30% to 69%, that are between 0.5 to 1 carat can be $100 to $2,500 and those 1 carat and above can ask up to $6,000/ct.

Cat's eye alexandrite
Cat’s eye alexandrite

Type
These magical stones do appear with a cat’s eye like other chrysoberyls. Alexandrites with cat’s eye are usually cut into a cabochon to maximize the cat’s eye effect. The cabochons can be translucent to opaque and very light to very dark body tone. Similar to opal, darker tones are more valuable because they act as a contrast for the cat’s eye to shine through. Even though cat’s eyes are even more rare than faceted stones, faceted cut alexandrites are still more valuable.

Imitations
Alexandrites can be synthesized in labs from corundum; a common practice in Russia so the labels can have “from Russia.” In addition to being synthesized in labs, alexandrites can also be made from synthetic color-changing sapphires with the help of vanadium. With these two forms of imitations on the market, be careful when shopping for gemstones overseas, especially from developing world countries.

There are a few natural gems that may have color change effects that can be confused as alexandrite. Some Sri Lankan spinel can appear violet in daylight and violet-red in artificial light, while some Tanzanian sapphire can change from brown-green to red that can look like alexandrite. Garnet, the most convincing mimic, can also display color change that are intense like alexandrite.

Prospect buyers should look for certified alexandrite whenever possible from reputable dealers.

In closing, remember that each stone is unique as the person buying it. You can go for smaller alexandrites with good color change if that’s what you prefer or larger ones with weak color change; both will end up about the same price since color change is the biggest factor in valuation. Choose a stone that speaks to you and you will be more happy wearing or adding it to your collection.

Alexandrite: Jewel of Russian Nobility


After covering tanzanite, a very rare gemstone, it is only fitting to cover another rare gemstone, alexandrite.

Discovered in Russian emerald mines in 1834, this rare gemstone was named after Czar Alexander II. Since this magnificent stone displays both red and green, the military colors of 19th century Russia, alexandrite easily became the national gemstone of old Russia and royalties across Europe.

Alexandrite under different light
Alexandrite under different light

Besides its rarity being a factor, quality alexandrites have become one of the most expensive gemstone due to its one unique property. That captivating property is the ability to change color. Green to bluish-green in sunlight and red to purplish-red in artificial light; basically, emerald by day and amethyst by night.

Not all colors are equal, however, colors of brown or grey is not desirable and will lower the value of the gem. The more noticeable the color change, the more valuable the gem. Natural Russian alexandrites above one carat are one of the most expensive gemstones in the world.

Another property that these gems can display is a cat’s eye, or chatoyancy. Chrysoberyl is known to display this effect but not many know that alexandrite can as well. This property will increase the price of any alexandrite lucky enough to possess it; major bonus would be one with color change.

An impure variety of chrysoberyl, alexandrite contains the major elements of beryllium, aluminum and, importantly, chromium – a rare element in nature – that do not normally occur together. It is chromium in the matrix that gives alexandrite its characteristic. In addition, there’s no silica, a very common element on the Earth’s crust, in which emeralds would form instead. The chance that chromium is at the right place, under the right conditions, is what makes alexandrite so rare among the world of gemstones.

Alexandrite with cats eye
Alexandrite with cats eye

Principality found in Urals, Russia, the deposits there have since been exhausted and, with that, the world’s quality supply of alexandrites were gone. Although found later throughout the world, a quality source with noticeable color change and strong colors was not found until 1987 in Minas Gerais, Brazil.

Although the green color is not as strong as its Russian counterpart, the Brazilian deposit is currently the main source of alexandrite. Even though more deposits have been discovered since the original in 1834, this gemstone is still very rare, especially those of fine quality. Alexandrites from Russia will fetch a highest price, with Brazil right behind it.

Alexandite ring with two colors
Alexandite ring with two colors

With a hardness of 8.5, which makes it great jewelry gem for daily wear without much special care needed, alexandrite rings are the most popular choice of jewelry for this gemstone due to the fact that the wearer can easily see the gemstone change its color with minimal effort. Of course, any facet alexandrite is a behold to see rather it’s on a pendant, necklace, or bracelet.

Lacking the history of many other colored stones, as its uniqueness is not immediately apparent, alexandrite will captivate anyone once they appreciate its sensational color change. There’s also the appeal of owning a stone that once only belonged to royalties, since many of the gemstone mines in Russia were owned by the Czar. For some, the prestige of finding rare gems is what attracts them this particular gem, as there are few rarer stones than this dual color stone. Whatever the reasons, there is no finer stone than the beautiful alexandrite.

Buying Tanzanite Guide


Being such a recent discovered gemstone, tanzanite is a complex gemstone for many to buy due to the stone’s ability to shift colors, or pleochroism, unlike more straightforward and well known gemstones like ruby and diamonds.

Despite being so new to the precious stone world, tanzanites have quickly become one of the most sought after gemstone in relatively short period; this quick guide is to help those understand better what to look for when buying these magnificent stones for the first time.

First and foremost, tanzanite is name for the blue variety of zoisite. Most on the market are yellow-brown zoisites that have been treated with heat to turn them blue; natural tanzanites are very rare and expensive. Unlike the diamond market, tanzanite prices are purely based on supply and demand, meaning prices will fluctuate.

Tanzanite is graded similar to diamonds, using the four C’s: color, clarity, carat and cut.

Deep blue tanzanite trillion with purple play.
Deep blue tanzanite trillion with purple play.

Color
As with other colored gems, color is the most important factor in depending the value of the gem. Deeper and more saturated blue is considered the most valuable and rarest. Most deep blue tanzanites are larger specimens of over 2.5 carats, while the smaller tanzanites are generally paler in color; be cautious of deep blue stones under 2.5 carats.

Of course, you should pick a shade of blue that is special to you. Maybe you like a bit more purple than blue; perhaps a light blue. Whatever, the case, do not in industry standard sway what’s right for you.

When buying them in person, remember that yellow, indoor lighting will make the stone appear more purple; while white, outdoor light will make it appear more blue. Knowing how your tanzanite behaves under certain lighting will help you determine the appropriate occasion to maximize the desired color. Does it look better during a stroll in the park or a evening, indoor party?

Clarity
Clarity refers to how many inclusions or flaws are seen within the stone. Unlike diamonds, however, tanzanites can only have “eye clean” as its highest clarity ratings, which means there’s no visible inclusions to the naked eye. Luckily, tanzanite is usually found with relatively clean crystal matrix so “eye clean” is the standard for this enchanting gem.

You will encounter many vendors using diamond grading terms like “VS” and “VVS”; these terms do not apply to tanzanites but they are used regardless due to the familiarity of them in the industry.

Carat
A factor we can all understand. By definition, a carat is one fifth of a gram so five carats equals to one gram. As stated above, higher carats mean the gemstone will have a deeper blue color and higher asking price.

A fun fact, tanzanites are lighter, in terms of weight, than diamonds. You will get a larger stone of tanzanite compared to diamond with the same carat weight.

Cut
Besides giving the gemstone a shape, the cut is suppose to enhance the brilliance of the stone. Of course, the cuts should be clean and symmetrical; if your eyes notice something off, the cuts might be truly off and a sign of a poor cut.

Unlike many other colored gemstones, each tanzanite is quite unique as its pleochroic properties means that the cutter must choose a good angle and style of cut to enhance the purple aura around the stone or focus on the blue color, thus making each gemstone very personal to the cutter and buyer.

Heat Treatment
Over 90% of all tanzanites on the market is heat treated to enhance the color. Most tanzanites on the market today are actually heat treated yellow or brown zoisites. Natural radiant blue is very rare and, obviously, very expensive.

Tanzanite silver ring with diamonds.
Tanzanite silver ring with diamonds.

Jewelry
Tanzanite is not a hard stone like diamond and more likely to chip when struck on hard surfaces. Pendants and necklaces make excellent choices as they keep the gemstone relatively safe. Of course, rings are still a viable choice; just be careful with them.

Investment
As one of the rarest gemstone in the world, found only in small region in Tanzania; tanzanites do offer a nice niche for those looking to invest in a gemstone as another deposit is unlikely to be found. Existing known deposit of this beautiful gemstone will probably be mined out in a decade or so.

For example, Paraiba tourmaline, discovered in 1980’s, was mined out in 1990’s and now can command about $20,000 per carat. Alexandrite, another extremely rare gemstone, has a similar asking price as Paraiba tourmaline. Both gemstones were at the price of tanzanite, back when they were actively mined.

What should you collect if you are looking for an investment? Well, the simple answer is the finest and rarest pieces with great color saturation, the 1% of tanzanites, as this is the industry standard to seek the most vivid colors in colored gems. These will fetch the best return on investment as they will be highly sought after by people in the trade and other collectors. For those on a budget, stick to the same criteria but go for smaller fine stones for the best return on investment.

As for size, the larger the stone will always grab the attention of would be buyers but smaller sizes between 1 and 2 carats are great options as well. Keep in mind that the tanzanites over 2.5 carats have the best chance of deep blue. A mix approach might be the best way to collect them.

Tanzanite: Gem of Mount Kilimanjaro


A gorgeous and radiant blue gemstone, tanzanite is beautiful as the majestic mountain that overlooks the only deposit found, in northern Tanzania, near the base of Mount Kilimanjaro. Being a blue variety of zoisite, tanzanite is the second most sought after blue gemstone in the world, only behind sapphire, and one of the top ten selling colored gemstones; quite remarkable for this gem when you realize when it was discovered.

Tanzanite with tinge of purple
Deep blue tanzanite with plays of purple

Discovered in 1967, tanzanite was introduced – and named – to the world by the famous jeweller Tiffany & Co. and quickly captured the imagination of gem enthusiasts around the world in part due to the relentless promotion by Tiffany & Co., lust blue colors, and the simple fact that it was the newest gemstone discovered in about 100 years.

Tanzanite displays a alluring blue that range from deep blue to light violet-blue with the most sought after colors are vivid blue with surrounding hint of purple or violet. Yes, this enchanting gemstone has pleochroic properties, or the ability to display different colors depending on the viewing angles, that further propel its popularity among buyers around the world. However, tanzanite’s pleochroism can only truly be appreciated when the stone is over 10 carats.

Pleochroism of tanzanite
Pleochroism of tanzanite

This pleochroic feature does make it a difficult stone to cut because a skill craftman is needed to find the best angle and correctly cut it to maximize the blue color, any plays of purple and minimize any shades of brown or yellow; due to zoisite having a wide range of colors that include colorless, gray, yellow, brown, pink, green, blue, and purple.

Of course, this gemstone would not be rare if for the fact that most raw crystal tanzanite will have tints of yellow or brown. To fix this, experienced cutters heat the raw crystals to about 500-600°C to remove the unwanted colors by changing the oxidation state of the vanadium in the crystal structure while being careful there are no inclusions as these will fracture the gemstone during the heating process. This procedure is common in the trade, however, as nearly all gems sold as tanzanite was treated with heat; natural tanzanite is very rare.

Because of their lust and vivid blue color, tanzanite is best set against silver to, literally, let the gemstone shine; better still is to surround it with diamonds. But with a hardness rating of 6.5 Mohs, one should be careful when handling and wearing tanzanite jewelries. Although rings are always a popular choice, its semi soft ratings is better suited for pendants and necklaces to avoid hitting hard surfaces.

Natural rough tanzanite
Natural rough tanzanite

Although the deep blue and tinge of purple is what grabbed people’s attention around the world, for many, what really hook many gem collectors is that fact that natural tanzanite is only found at one location, within a few square miles of land, and it’s in limited supply. Soon, the mines in Tanzania will be exhausted in a few decades, unless a new deposit can be found; an extremely short span when you consider that many gemstones have been around for centuries or thousands of years.

Lastly, for those looking to buy tanzanites as an investment, like all investments, no one can predict what will happen when the mines at northern Tanzania are depleted. Will the prices sharply increase? Will it motivate surveyors to search wider and deeper for new sources of tanzanite? Or will people just go back to more known and cheaper gemstones? Regardless of what happens, tanzanite is a wonderful addition to your personal collection and on you. If you haven’t notice the gem before, you will have no problem noticing this enchanting gemstone now.