August 2013 Newsletter: Fine Sapphire from Madagascar

Sapphire has been mined in Ceylon for centuries, but Madagascar became known for sapphire a mere 15 years ago. When major sapphire desposits were found in Madagascar in 1998 the country was gripped by a gemstone fever reminiscient of the 1849 gold rush in California. The deposits were so important that by 2007 Madagascar had became the leading producer of high quality sapphire in the world. 


Madagascar is an enormous island located in the Indian Ocean off the southeastern coast of Africa. It is the fourth largest island in the world -- after Greenland, New Guinea and Borneo -- with a land area of more than 587,000 sq. km, larger than Thailand, Spain or Sweden. But due to its isolation, Madagascar has a unique ecology, with more than 80% of its animal and plan species found nowhere else on earth.

Madagascar was an independent kingdom that became a French colony in 1886 and regained its independence in 1960. With a population of about 22 million, it remains one of the poorest countries in the world. But geologists believe that the country has some of the richest untapped mineral resources in the world.

The discovery of significant gem deposits began with some small finds in the southern part of the country in the early 1990's. But the major sapphire deposits discovered in 1998 in the tiny village of Ilakaka in southern Madagascar came as a huge surprise to the gems world.

The country is now known to have sapphire deposits in both the north and south regions. The two regions are geologically distinct. Sapphire deposits in the far north result from alluvial deposits of weathered basaltic rocks, while those in the south are of metamorphic origin. Many of the blue sapphires from the north have a green secondary hue, while those from the south tend to be a pure blue.

Madagascar is most famous for blue sapphire and ruby, but many different colors of corundum have been found, including pink, yellow, green, white and padparadscha. Some fine color change sapphires have also been found, that display blue or violet depending on the lighting. However, it is not just the quantity and variety of material that has made Madagascar so important as a sapphire producer. Rather it is the combination of the quality and size of the gems, a combination that had not been seen in the gems business for many years.

As gem mining has developed, high quality specimens of other gems varieties have also been found, including aquamarine, morganite, rhodolite and color change garnets, tourmaline, apatite and sphene. Mining in Madagascar is still in the early days and we expect that significant new deposits will continue to be discovered. Just last year huge sapphires and rubies were discovered in a national park near Didy in northeastern Madagascar. Miners rushed to the mine but the police soon cordoned off the area to prevent illegal mining in the forest preserve.


Notable Gems from the AJS Collection

This month we feature fine untreated gems from Madgascar, including sapphire, ruby, aquamarine, garnet and sphene.

Click on a photo to see the details for the item.

2.02 ct Unheated Ruby, Madagascar

2.02 ct Unheated Ruby from Madagascar

An exceptional 2 carat unheated ruby in a vibrant pure red. This rare gem displays remarkable clarity for ruby (graded "almost loupe clean"). Certified as natural and unheated by Tokyo Gem Lab (TGL).

See the video

4.52 ct Color Change Garnet, Madagascar

4.52 ct Color Change Garnet from Madagascar  [SOLD]

A gorgeous example of the fine Malagasy color change garnet in a large size. Displays a great color change to a deep strawberry under incandescent light. Very clean (graded "almost loupe clean") and well cut with full brilliance.

1.86 ct Unheated Pink Sappphire, Madagascar 

1.86 ct Unheated Pink Sapphire from Madagascar  [SOLD]

A sweet pink sapphire with great sparkle and fire. Nice shape with excellent luster, this is as pretty a pink sapphire as you will find. This fine gem will make a romantic piece of jewelry that you and your family will treasure. Certified as natural and unheated by Tokyo Gem Lab (TGL).

19.51 ct Aquamarine, Madagascar

19.51 ct Aquamarine from Madagascar  [SOLD]

A very fine aquamarine from in a very impressive size, over 19 carats A lovely sea blue, this fine gem combines excellent color saturation with superb clarity and precision cutting. Completely natural and untreated.  $5,853 

 19.96 ct Sphene, Madagascar

12.96 ct Sphene from Madagascar  [SOLD]

A top sphene from Madagascar in a rare chrome green. Well cut to maximize the fine color and dazzling fire, this elegant cushion will set up beautifully in a ring or pendant. Guaranteed natural and untreated.  $4,600


News from AJS and the Gems World

  • Dr. Dietmar Schwarz from Gubelin to head AIGS Bangkok lab

    According to a story in Diamond World, Dr. Dietmar Schwarz, long time head of research at the Gubelin Lab in Lucerne, will join the Asian Institute of Gemological Sciences (AIGS) in Bangkok as director of their laboratory. Dr. Schwarz, one of the leading research gemologists in the world, will reportedly take up the position in Oct 2013.

  • $136 million Jewel Theft in Cannes

    A lone armed gunman stole gems and watches worth an estimated $136 million from an exhibition of Leviev diamonds at the Carlton Hotel in Cannes on July 28th. The theft took place at midday, in the presence of 3 unarmed security guards. The Carlton is where Alfred Hitchcock filmed To Catch A Thief, his 1955 film about a jewel thief operating on the French Riviera. 

  • Diamonds lose their sparkle, as women choose colour

    A BBC new story from July 30th notes the growing popularity of colored gemstones around the world, as more women (and men) choose colored stones for engagement rings and other important jewelry purchases. One effect of changing consumer preferences is that prices for sapphires and rubies have risen faster than diamonds over the past 8 years.


Ask the Gem Experts

Each month we answer questions from our customers. We welcome your questions and you can submit a question from our contact page.

Love your newsletter!  How does one detect if a sapphire is glass filled? Thank you, SL, USA

Generally it takes an experienced eye and some gemological knowledge to detect glass-filling in sapphires.

Sapphires that have been filled with cobalt-doped glass will show a strong red or orange-red when viewed under the Chelsea filter (natural and synthetic blue sapphire will not show red). In addition, the glass-filled sapphires will not display pleochroism when viewed with a dichroscope, since the blue color comes from the cobalt in the glass rather than from the structure of the sapphire. 

For the consumer, price is your best clue. If you see blue sapphire selling for $25 or $30 a carat, you can be fairly sure that is either glass-filled or synthetic.


How would you compare the merits of sapphire and tanzanite? Why is sapphire so expensive compared to tanzanite? VN, UK

Tanzanite has many attractions. The highest grades of tanzanite display a vivid violetish blue that rivals fine sapphire. Tanzanite can also routinely be found in larger sizes (over 4 carats) that are very rare in sapphire. Tanzanite also tends to have excellent clarity, and loupe clean specimens are not uncommon. But tanzanite is not nearly as durable as sapphire -- it has a hardness rating of 6.5 compared to 9 for sapphire. The main reason that blue sapphire is subtantially more expensive is its rarity. Clean sapphires in a saturated blue are very rare, especially in sizes over 2 carats. Prices on fine sapphire tend to rise exponentially with carat weight, while tanzanite prices per carat tend to be fairly constant even in larger stones.



All the best in gems,

Arnold, Rung & Ron