September 2019 Newsletter

Santa Maria Aquamarine

 

Aquamarine, the blue or greenish-blue color of the mineral beryl, is one of the most popular of colored gemstones. It is valued for its excellent hardness (7.5 to 8 on the Mohs scale) and its delicate color and excellent transparency. It is also one of the few fine gemstones that can be found in large sizes at affordable prices.
 
Aquas can rangle in color from blue to green, but the pure blues are the more valuable. Green aquas are often heated to reduce the yellow, so a clean unheated blue aquamarine with good color saturation is a rare and valuable gem.
 
All aquamarines are pastel in color, but some are so light as to be pallid. Darker-toned aquamarines usually command the highest prices in the market. But color saturation should not be confused with tone. Some of these darker toned aquas actually have quite a bit of gray and are not nearly as attractive as lighter toned gems in a purer blue.
 
The finest Aquamarines come from the Santa Maria de Itabira mine in Minas Gerais, Brazil. They are famed for their unusually deep blue saturation. The 2.35 ct matched pair in the video above are an excellent example. We also have an outstanding 4.19 ct cushion in this month's Notable Gems.
 
These days it is common in the gem trade to see any deep colored Aquamarine referred to as "Santa Maria" color, regardless of its origin. You may see the deep-toned Aquamarines from Mozambique referred to as "Santa Maria Afrique." The Brazilian Santa Maria gems are especially prized by collectors, particularly the saturated blues with minimal grey.
 

 

 

Notable Gems from the AJS Collection

This month we feature fine blue gems from our collection, including two Santa Maria Aquamarines along with Gem Silica, Tanzanite, Blue Tourmaline and Apatite. Click on any photo to view the details for the gem.

4.19 ct Aquamarine from Santa Maria, Brazil
The finest Aquamarines come from the Santa Maria de Itabira mine in Minas Gerais, Brazil. They are famed for their unusually deep blue saturation. This gorgeous square cushion is an outstanding example, with an especially deep color. This is beautifully clean material, perfectly cut, that will make a special ring for the Aquamarine connoisseur. Guaranteed natural and untreated.

See the video

4.70 ct Royal Blue Tanzanite from Tanzania

A superb Tanzanite with a bright and vibrant color. This lovely oval displays a rich sapphire-blue with just a hint of violet that is rare in Tanzanite. This gem has been precision cut to bring out the full potential of this beautifully clean material. Guaranteed natural.

See the video

13.69 ct Gem Silica from Inspiration Mine, Arizona

The finest Gem Silica comes from the Inspiration mine in Arizona. The best of this material is an intense turquoise color with very good translucency. This bright and vivid fancy cabochon in a large size (35 mm long) is an excellent example, with a unique shape perfect for a stunning pendant. Guaranteed natural and untreated.

See the video

2.42 ct Vibrant Blue Tourmaline from Namibia

A superb loupe clean, Vibrant Blue Tourmaline from the recent find in Nambia! This is beautiful crystal with a gorgeous saturated blue color, in an elegant cushion that will set up beautifully in your jewelry design. You will be amazed at the color of this rare Tourmaline, it will be an important addition to any gem collection. Guaranteed natural and untreated.

See the video

6.31 ct Blue Apatite from Madagascar

A vivid Teal Blue Apatite from Madagascar with a bright open color. Over 6.3 carats, this fine clean gem will set up beautifully in your jewelry design. Guaranteed natural and untreated.

See the video

2.35 ct Aquamarine Matched Pair from Santa Maria, Brazil

This lovely matched pair of pear shaped Aquamarines is an excellent example of the superb blue saturation of some Santa Maria gems, with very little gray. These elegant pears are perfectly matched, completely clean and beautifully cut. Guaranteed natural and untreated.

See the video


News from AJS and the Gems World

GIA Review of Mozambique Ruby

In the last 10 years Mozambique has become the most important source for gem-quality Ruby. The latest edition of GIA's Gems & Gemology journal has an excellent review of the history of Mozambique Ruby, including the history of mining in the country and the different Ruby deposits and the unique gemological characteristics of the gems produced from each. The article also covers the various players involved in mining this material and bringing it to market.
 
It is rare to find such a comprehensive review, and one which illustrates so well the challenges of finding and extracting rare gems in a developing country.
 
This fine article is available online here:  A Decade of Ruby from Mozambique
 
 
 

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.

I've seen the terms "color change" and "color shift" used to describe gems that show different colors. Could you explain the difference between these two terms?  EM, USA

Color-change and color-shift gems display different colors under different lighting. "Color-shift" is used when the change is more subtle than a "color-change" gem such as Alexandrite.

So the difference is essentially a matter a degree. An example of a color-shift is when a stone changes part way between two adjacent hues, such as a Pink Malaia Garnet that shifts between pink and pinkish-red. A color-change gem shifts completely to an adjacent hue -- such as the Royal Purple Garnets that change from grape to cranberry -- or to a non-ajacent hue, such as Alexandrite's change from green to purple.

 
 
 
 
 

All the best in gems,

Ron, May & and Rung