April 2016 Newsletter: Rubellite Tourmaline from Africa

 

The tourmaline family is the largest and most diverse in the gemstone world and gemologists recognize 14 different varieties of tourmaline based on chemical composition.

Most of the tourmaline varieties have technical names such as elbaite, dravite and liddicoatite. But some types of tourmaline are so important in the gem trade that they have been given more descriptive names, such as chrome tourmaline, rubellite tourmaline, canary tourmaline and paraiba tourmaline. These names have become so accepted that they are now used by gemological laboratories in their reports.

Rubellite is the name used for the pinkish-red to violet-red tourmaline. The name comes from the Latin rubellus, meaning reddish. Sometimes the name rubellite is used loosely to refer to any pink or pink-red tourmaline, but the name is more appropriately reserved for the most vivid and saturated colors. This is sometimes expressed by saying that the intense color of rubellite holds up well under different types of lighting, without showing a tinge of brown under artificial lighting.

Pure red rubellites can be found, but they are very rare. The most typical color is an intense pinkish red that is one of the most vivid colors found in any gemstone variety. Since rubellite can also be found in large sizes, it makes stunning jewelry.

Rubellite typically has significant inclusions. So long as the inclusions do not make the gem appear milky or cloudy, they do not affect the value of a finely-colored stone. Rubellite may sometimes be heated at low temperature to improve the color or clarity, but this is a risky strategy since inclusions can produce cracks when heated. So usually rubellite is completely untreated.

The leading sources for high quality rubellite are the main tourmaline producers: Brazil, Madagascar, Mozambique, Nigeria and Pakistan. We have found some exceptional rubellites from Nigeria and Mozambique in recent years, including several stones over 50 carats. Recently we acquired some bright pink reds from Mozambique, such as the 5.09 ct pear in the video above, that are wonderfully vivid. 

See our collection of Fine Rubellite Tourmaline

 

Notable Gems from the AJS Collection

This month we feature recent acquisitions to our collection.

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

0.72 ct Unheated Ruby, Mozambique

0.72 ct Unheated Ruby from Mozambique  [SOLD]
 
An exquisite pink-red ruby from Mozambique with exceptional fire. This is beautiful material, completely untreated, with wonderful brilliance. Certified by GemResearch Swisslab (GRS) as unheated. This is an amazingly bright gem that will sparkle in your jewelry design.
 
4.70 ct Bi-Color Tourmaline, Nigeria

A unique watermelon tourmaline in delicate pastels. Perfectly clean with excellent cutting and polish, this is just a lovely gemstone. Guaranteed natural and untreated.

See the video

6.68 ct Rhodlite Garnet from Umba River, Tanzania
6.68 ct Rhodolite Garnet from Umba River, Tanzania  [SOLD]
 
A fine rhodolite trillion from the Umba River region of Tanzania (sometimes known as Umbalite Garnet). This is an impressive gem with a rich orange-red hue, displayng excellent fire. Very clean and nicely cut, this fine gem will set up beautifully in a ring or pendant. Guaranteed natural and untreated.
 

7.64 ct Amethyst, Uruguay

7.64 ct Amethyst from Uruguay [SOLD]

A splendid round amethyst from Uruguay in an intense deep purple. This fine amethyst has excellent color saturation without being too dark, and displays bright violet flashes as it is turned in the light. At 12.85 mm, this beautiful gem will make an impressive piece of jewelry. Guaranteed natural and untreated.

10.69 ct Chrysoprase, Australia

An outstanding large gem chyrsoprase from Australia with a delicious apple-green color and excellent translucency. This gem displays the wonderful luminosity that is characteristic of the very best chrysoprase. Nicely fashioned as a sugarloaf cab this is a unique piece. Guaranteed completely natural and untreated.

See the video

5.09 ct Rubellite Tourmaline, Mozambique

5.09 ct Rubellite Tourmaline from Mozambique  [SOLD]

A stunning rubellite tourmaline in a vivid pink-red that really pops. This a clean gem with a bright and intense color that you can see from across the room. Guaranteed natural and untreated.

See all our Rubellite Tourmaline


News from AJS and the Gems World

  • Gems & Gemology features Grandidierite from Madagascar

GIA published an article on Grandidierite in the Winter 2015 edition of their journal Gems & Gemology. The article notes that "The mineral is very rare; gem-quality material of facetable size was almost unheard of in the market before the summer of 2015." They go on to note that they first issued several reports on grandidierite specimens in September 2015, when AJS Gems first submitted some high quality grandidierites for certification. GIA issued special reports on several of our gems, noting for example,  that ""Very fine, large gem-quality grandidierite with high degree of transparency and distinctive color like this 4.54 ct gemstone can be considered extremely scarce."

The GIA article includes: "With field collection and lab testing pointing to new sources of grandidierite, this could be a step toward a larger market presence for this material."

 

  • De Beers Oval Blue Diamond Expected to Fetch up to $35M at Sotheby's

Sotheby's is expecting a price above $30 million for a 10.10 ct blue diamond at the Magnificient Jewels sale in Hong Kong on April 5th. It is the largest oval fancy vivid blue diamond ever offered at auction. The gem is from an Asian private collection, and is the only oval-shaped stone among the twelve rare diamonds that form the De Beers Millennium Jewels collection unveiled by De Beers in 2000 in celebration of the millennium.

 

 

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 subscribed to your newsletter and read it on my mobile phone each month, it's really great to do that. But how do I read the older newsletters that came out before I subscribed? Your help appreciated, PD, USA

From your mobile, you can see the index of all our newsletters and articles by tapping on the main menu icon ☰ and selecting "Education". If you access our website from a PC or tablet, click on the "Education" tab on the main menu and selected "Gemstone Articles".

 

I am interested in black star sapphires. I see them offered at different prices and I wonder what the quality differences are that make some more expensive. Can you help me understand the pricing on these gems? KB, Australia

The main quality issue with black star sapphires from Thailand is that many stones in the market are low quality material that has been fracture-filled with lead glass. The treatment is not stable -- it can be affected by heat and common acids and household cleaners -- and we recommend against buying fracture-filled sapphire and ruby.

We guarantee that all our star sapphires are completely untreated. Jewelers can set these stones with confidence, and you can be assured of a high quality sapphire that will last a lifetime (or more).

 

 

 

All the best in gems,

Arnold, Rung & Ron

 

 
 Email to a Friend Friend's Name:
Friend's Email:
Your Name:
Message: