All posts by RareSource


6ct Unheated Sri Lankan Ruby

Celebrating July’s Birthstone

Ruby has long been associated with the Sanskrit word Ratnarāj, meaning “king of gems”, and has been admired and sought after by royalty, celebrities and collectors throughout history

When Queen Elizabeth II was married in 1947, she was gifted a ruby necklace by the people of Burma. In 1973, Garrard & Co. set 96 fine rubies from the necklace into an iconic tiara. She named this diadem the Burmese Ruby Tiara to honor the generosity of the people of Burma (now Myanmar)

In the 1920’s and 30’s, star rubies and sapphires were very popular amongst the Hollywood elite. The “Star of Burma”, an 83ct cabochon cut star ruby, had a starring role in three 1937 films: Hollywood HotelManhattan Merry-Go-Round and Vogues of 1938, where it was set in a deco bracelet by Trabert & Hoeffer (Mauboussin). These appearances played their part in making it as famous as the actresses it adorned
 Elizabeth Taylor’s vast jewelry collection is known throughout the world, and ruby was one of her favorite gemstones. While on vacation in the Côte d’Azur in 1957, her husband Mike Todd gifted her with a breathtaking ruby and diamond necklace, earring and bracelet set from Cartier. Todd died tragically in a plane crash just one year later. In 1968, her then-husband Richard Burton gave her an 8.25ct ruby and diamond ring by Van Cleef & Arpels for Christmas. Her jewelry collection was sent to auction at Christie’s in 2011, where the 8.25ct ruby and diamond ring sold for $4.22 million, and the ruby and diamond necklace sold for $3.7 million

This short video captures Elizabeth Taylor’s excitement the moment she received
 the Cartier ruby and diamond suite from her husband, Mike Todd, in 1957
6ct Unheated Burmese Ruby

Notable Ruby Auction Results:

  • 2012 – 32.08ct “Hope Ruby” sold for $6.74 million
  • 2012 – 173.09ct total weight, JAR Ruby Flower Brooch sold for $4.5 million
  • 2014 – 8.62ct “Graff Ruby” sold for $8.6 million
  • 2015 – 25.59ct “Sunrise Ruby” sold for $30.3 million
  • 2015 – 15.04ct “Crimson Flame Ruby” sold for $18.3 million
  • 2015 – 48=120ct Etcetera Ruby & Diamond Necklace (rubies ranging from 1-7ct) sold for $13 million
  • 2016 – 15.99ct “Jubilee Ruby” sold for $14.1 million
  • 2016 – 10.05ct “Ratnaraj Ruby” sold for $10.2 million
  • 2017 – 15.03ct Unnamed Ruby sold for $13 million
  • 2019 – 11.20ct “Dupont Ruby” sold for $8.95 million
7ct Unheated Burmese Ruby with Crystals on Matrix

Photo by J. Scovil

The mines in Mogok are still officially closed, so production continues to be minimal, and therefore, prices have remained strong. In contrast, production at the Monte Puez ruby deposit in Mozambique is still producing considerable supply, meeting much of the global demand. Smaller deposits in Vietnam, Tanzania, Madagascar and Afghanistan have had limited production, particularly in recent months, due to health concerns 

179ct Burmese Ruby Crystal

Mineral collectors and museums value crystals like this specimen from Burma, making it worth more as a mineral specimen than the faceted gems it would yield
5ct Unheated Ruby with Crystal on Matrix

Featured in Gems & Gemology: Special Geographic Origin Issue
Winter 2019, Page 461
Photo by R. Weldon


This has been the longest stretch of time I’ve spent without setting foot on an airplane in the last 30 years of my life… This period has had me reminiscing and cleaning out the office a bit.  As we were editing files and purging our cabinets, I came across these early travel photos of my first trip to Tanzania in 1991. The world was a different place and travel was easier in many ways. This was pre 9/11, pre SARS, pre H1N1, pre CORONA, it felt free… like the world was mine to navigate. 

As a 25 year-old man on a mission to collect gem samples for the Gübelin Gemological Laboratory, I was filled with energy and excitement for the opportunity to visit several different mining locales. In Landanai, on our way to see the chrome tourmaline mine, we came across two young miners who persuaded me to follow them to their rhodolite garnet mine. We entered the mine using only the light from the flame of their homemade oil lamp. Entering the mine, I quickly became aware that we would be climbing about 30 feet down a set of alternating rock ledges, or shelves. As we continued, we came to the end of a short tunnel, where we were only able to dig for 10 minutes or so before the lack of oxygen extinguished our lamp. Luckily, I had a battery operated flashlight and we were able to climb our way back out. We found only very poor quality rhodolite nodules in the mine, but were able to buy a few nicer pieces from the miners. As we journeyed to the main Landanai mine, a tower of giraffes greeted us along the dusty path, providing a perfect photo opportunity with Mt. Kilimanjaro in the background competing for stardom.

The next duo of photos is of the terrain and earthly findings of the Landanai mine, showing the weathered pegmatite on the left and rich green chrome tourmaline crystals in matrix on the right.

The camp was crafted of several typical mud-walled bush houses, surrounded by sparse vegetation and free range chickens, one of which was masterfully prepared by the cook and camp mother sitting to my right in the kitchen hut. 

A few days later, we visited what were then called Blocks A, B and D of the tanzanite mine in Merelani. These areas were not officially open to visitors, but we managed to gain access since we were there as gemologists collecting samples and documenting the mining process.

In the above photo, you can see the numerous tin roofs covering independent mine shafts in Block D. In the background is Block C, which is where mining giant, Tanzanite One, had its concession for many years. Following in the next two photos are typical independent small-scale mine shafts in Block D with a motorized lift for transporting miners, tailings and gem material.

Meeting the people was a true highlight of the trip, and learning about their days, their mining methods and sharing experiences enriched my soul. The knowledge I gained helped me understand some of the challenges they face; from something as simple as the mine foreman using a flashlight strapped to his head as his mining light, which prompted me, on my next trip there, to bring mining lights to give to the miners. Our ease of life and access to supplies kept me from realizing that the miniature batteries required to operate the small, lightweight lamps weren’t readily available near most mining areas. Now I bring replacement batteries, which are probably more valuable than the lights themselves. The miners are an incredibly resourceful crew and can make many of the items they need, as evidenced by the photo of an enterprising miner using a modified bicycle to power a tool sharpener. 

During my visit, several miners and dealers showed me rough samples of a newly discovered, unknown green gem. Due to its trichroic colors, readily visible using a dichroscope, I suspected that it might be zoisite. This was further supported when I visited renowned gem dealer and author, Dr. N.R. Barot, in Nairobi, who had collected and cut various colors of zoisite, including some greenish colors that strongly resembled the material I had seen at the mines in Merelani and with dealers in Arusha. When I returned to the Gübelin Lab with the rough and cut stones I had collected, advanced testing confirmed our suspicions that this new green variety of zoisite was indeed tanzanite. Dr. Barot and I then co-authored an article on the new, gem quality green zoisite that was published in the Spring, 1992 edition of Gems and Gemology.

I have savored my moments at home, in my office and with my family, but I look forward to traveling again soon and feeling that same anticipation of the unknown, the fresh find, and new adventures. 

– Edward 


23ct Rhodolite, 20ct Tsavorite and 32ct Spessartite Garnets
Photo by: Mark Mauthner

The name “garnet” is derived from the Latin “granatus”, referring to the resemblance garnet crystals share with pomegranate seeds

Garnet has a history of appreciation dating back thousands of years, from the time of the Egyptian pharaohs to the Greco-Roman period and through the Middle Ages. It was one of the most favored gems of religious, political and social leaders to signify status

The garnet group of gems is made up of the end-members pyrope, almandite, spessartite, grossular and andradite

Deep red Bohemian pyrope garnets, discovered in the early 16th century, helped increase availability of garnet for the middle class, and thus made it a more mainstream gem until the late 1800’s

Fun Fact: the word “pyrope” stems from the Greek words meaning “fire eye”

40.66ct Rhodolite from Tanzania
Photo by: Robert Weldon

Rhodolite garnets are a pyrope-almandine mixture that range in color from purple to purplish-red. This 40.66ct purple rhodolite from Tanga, Tanzania, is an extremely large example of this material

Grossular Garnet Rough and Cut
Photo by: Jeff Scovil

Garnet has a high to very high refractive index range, from pyrope and grossular at approx ~1.74 to rhodolite at ~1.76 to spessartite at ~1.80 and andradite at ~1.88. Gemologists use refractive index, specific gravity, absorption spectra and inclusions to differentiate garnet’s end-members and varieties

8ct Tsavorite
Photo by: Robert Weldon

Tsavorite is the rich green variety of grossular garnet discovered by Campbell Bridges in 1967 in Tanzania, and again 3 years later in Kenya

Demantoid Garnets from Ural Mountains in Russia
Photo by: Robert Weldon

Andradite garnets range in color from brown to the vivid green of highly sought after Russian demantoids. The cause of this vivid green color is due to trace amounts of chromium, while iron gives it a more yellowish appearance. The discovery of Russian demantoid garnet in 1854 added an exciting new color variety to the garnet family, which designers eagerly embraced. The initial source was quickly depleted but left a lasting mark on the industry that allowed for its resurgence when material reentered the market after the Cold War. Today, commercial quantities of demantoid are available from Russia, Namibia and Madagascar

Fun Fact: Andradite’s dispersion is 0.057, which is higher than that of a diamond at 0.044

Demantoid Crystal in Matrix
Photo by: Jeff Scovil

Garnets typically form under metamorphic or metasomatic conditions in which preexisting igneous or sedimentary rocks are altered by heat and pressure due to tectonic forces or contact with an igneous intrusion

Red hessonites (above right), a variety of grossular, enjoyed increased production in recent years from Southern Sri Lanka, providing a more affordable alternative to red spessartite

Spessartite Garnet Crystals and Gems from Tanzania & Nigeria
Photo by: Jeff Scovil

Gem quality spessartite crystals are found within metamorphosed schists. These crystals occur as euhedral or subhedral rhombic dodecahedrons (24 faces) which can sometimes look almost spherical

Namibian “Mandarin” Spessartites ranging from 0.92ct to 10.25ct

These vivid orange spessartites are extremely rare, usually occurring in sizes less than one carat. They were discovered by a farmer in 1992 along the Namibian border with Angola. The cause of this remarkable color is Manganese

12.18ct Malaia Garnet

Malaia garnets are a pyrope-spessartine mixture that often exhibit a color shift or even a color change, like the gem above. Recent increase in supply from Tanzania and Madagascar has helped make this a popular garnet in contemporary jewelry design

33.63ct Rainbow Garnet

Rainbow garnet from Alamos Mexico, New Mexico and Japan exhibits a play of color due to an outer layer of growth that creates diffraction grating-like interference colors

A new variety of garnet was discovered in Mali, West Africa, in 1994. Grossular-andradite, known in the trade as “Grandite Garnet” or “Mali Garnet”, has a chemical composition of (Ca,Fe)3Al2(Si04)3 and a refractive index range of 1.752 – 1.782. The color of most of the material ranges from yellowish-green to rich green to brown

Click below to see the Gems & Gemology, Fall 1995, article co-authored by Edward Boehm

Gem-Quality Grossular Andradite: A New Garnet From Mali


Violetish-Blue and Green Tanzanite (11 – 23ct)
Photo by Robert Weldon

Celebrating December’s Birthstone

Maasai traditions associate the color blue with new life, so it is only fitting that tanzanite, a stone discovered by Maasai herders in 1967, is the traditional gift for new mothers. It is, truly, the ultimate Birthstone.

A relative newcomer to the gem world, tanzanite has made a lasting mark on the jewelry industry. Mined only in one small area of a few kilometers in the Merelani hills, approximately 70 km Southeast of Arusha and Northwest of Mount Kilimanjaro, this rare stone is coveted by collectors and jewelers alike.

The rarest color of tanzanite is green, colored by trace amounts of chromium. Discovered in 1991, the local miners called it “combat”
because of its yellowish-green to bluish-green color. It is still considered one of the most collectable gems from Tanzania.

Read more about green tanzanite in this article by Edward Boehm and Dr. Barot – Gems and Gemology, Spring 1992

Maasai Warriors

Tanzanite was discovered in 1967 when wildfires engulfed the Merelani hills at the foot of Mount Kilimanjaro, naturally heat treating the material and exposing their striking blue-violet color.  A group of Maasai herders saw the exquisite stones and reported their findings to Portuguese geologist, Manuel D’Souza, who introduced this new discovery to the western world.

Tanzanite and Tsavorite Crystals
6ct Blue Tanzanite

Tanzanite’s strong pleochroism causes it to display a multitude of colors, primarily blue and violet. Depending on the lighting, a single gem can present as blue, violet and burgundy. This is due to the trace amounts of vanadium and/or chromium present during its formation. As with many gems, larger stones tend to appear in a deeper color than their small counterparts.

Independent artisanal miners in Block D 

Most tanzanite has to be heated to improve its color, which reduces or removes its reddish brown properties or improves color saturation.  Recently, natural color material has gained favor because of the strong pleochroic colors that can be manifested through skillful cutting.

8ct Pink Tanzanite


9.30ct Red Topaz

Like ruby, precious topaz gets its color from trace amounts of chromium (Cr+3). There are two theories as to how topaz derived its name. Some say it is named for the island of Topazios in the Red Sea, which historically produced peridot, while others believe it comes from the Sanskrit word tapaz or topas, meaning “fire”

Ancient Egyptians believed that topaz was colored by the golden glow of the sun god Ra.  Ancient Romans associated the stone with Jupiter, also god of the sun.  These myths were likely fueled by the gem’s array of fiery hues

8.24ct Pink Topaz from Brazil
RareSource selection of pink to red topaz ranging from 9.06ct – 24.04ct

The color most often associated with topaz is yellow, but it is actually found in orange, brown, red, blue, pink, violet, and colorless as well. Until geologists started identifying differences in mineral specimens about 200 years ago, all yellow and golden gemstones were labeled as topaz

Imperial topaz was named after nineteenth century Imperial Russia, and was so rare and beautiful that ownership of the gem was only granted to the royal family and those fortunate enough to receive it as a gift from the Czar

Washing for gem topaz at the Bela Vista Mine, Ouro Preto, Brazil
Photo Credit: Sergio Castro

Topaz formed in hydrothermal veins and is found in heavily altered schist that has turned into lateritic clay.

Waterworn Red Topaz Crystal Rough
Photo Credit: Sergio Castro

The Capão do Lana Mine, just outside of the village of Rodrigo Silva in Minas Gerais, Brazil, once produced the largest amount of imperial topaz worldwide. Mineral deposits were first recorded by the Portuguese in this location in 1751, and in 1768, they were discovered to contain topaz. The Capão Mine recently stopped operating but the Vermelhão, Dom Bosco, Boa Vista and Bela Vista are still producing. Read more about Brazilian Topaz in this article by Edward

See the amazing 48.86ct “Whitney Flame” red topaz in the Gem Hall of the Natural History Museum at the Smithsonian Institute in Washington DC


32.44ct Liddicoatite Tourmaline named in honor of Mr. Richard T. Liddicoat, former president of GIA
Photo by R. Weldon

Introduced to Europeans in the 1700’s, Tourmaline became known as the Muse’s stone and is said to assist in the creative flow of artists across many mediums

44.39ct Bi-Color Tourmaline

Fun Facts
Tourmaline contains pyro-electric properties. The Dutch discovered tourmaline’s ability to attract dust and ash when heated, and used the long, slender crystals to clean their meerschaum pipes by drawing out the ashes

Today this property, creating strong polarity, is used in hair styling tools

Tourmalines also have a piezoelectric effect that was first applied in underwater sonar systems and ultrasound technology
during the second world war

Teal Tourmaline 2.39ct – 9.44ct

 Tourmaline’s strong pleochroism, which means that the color appears differently based on the direction in which it is viewed, requires great skill in cutting to optimize the face-up color

Renewed artisanal mining activity in the Araçuai-Salinas district (made famous in the 1970’s and 1980’s) is producing unique colors as seen above

Rubellite Tourmalines from the Cruzeiro Mine 2.82ct – 14.14ct

The Cruzeiro Mine has been commercially operational since the 1940’s when the US mined mica there during WWII for electronic components.  Since the 1950’s, it has produced fine quality rubellite, indicolite, bi-color and emerald green tourmalines 

Edward standing in a Tourmaline pegmatite pocket at the Cruzeiro Mine with renowned Brazilian geologist/miner Odulio Moura
4.49ct and 3.29ct Paraiba Tourmalines
Photo by R. Weldon

Tourmaline ranges dramatically in demand and value, and the most desired is the Paraiba tourmaline from Paraiba, Brazil.  A relative newcomer in the gemstone world, these brilliant blue and green elbaite tourmalines were discovered in the late 1980’s.  Because of their scarcity and electric colors, caused by trace amounts of copper and manganese, they are now one of the most coveted gemstones in the world

Sri Lanka Flooding

In June of this year the island of Sri Lanka was hit by terrible flooding in the aftermath of tropical cyclone Mora. As a result a hill collapsed outside the gem trading town of Ratnapura, destroying at least fifteen homes and burying dozens of people. So far the casualty count for the flooding is around 150 people.  In an effort to help our friends and colleagues in the area, RareSource has partnered with the AGTA in donating to the Ratnapura Relief Fund. To give money to the Ratnapura Relief Fund, contact the AGTA at or 800-972-1162

14th Annual Sinkankas Syposium : Sapphire


We are pleased to announce that Edward has been asked to speak at this years Sinkankas Symposium. The symposium is an event where noted experts within the gem community are each asked to give a presentation on an aspect of the current years topic. Edward will be presenting on the relevant topic of Sapphire Origin Determination: Past and Present.  The event will be hosted at the Gemological Institute of America’s  Robert Mouawad Campus in Carlsbad, California.

AGTA Las Vegas 2016

The team at RareSource would like to thank Group shot Las Vegas 2016everyone who visited our booth and contributed to our successful show.  As usual our booth was filled with a large assortment of untreated and special gems. Some of our favorites included a 20ct tsavorite garnet, a 11ct+ vivid red spinel from Tanzania and a 14ct rich green paraiba tourmaline. As we reflect on the show  we are once again reminded how blessed we are to be able to work in such an incredibly diverse trade that is filled with so many friends.  We look forward to seeing you at the next show.