Mackay Emerald Necklace

Origin of name

The Mackay Emerald Necklace gets its name from  Mrs. Anna Case Mackay, the owner of the renowned necklace, who donated it to the Smithsonian's National Museum of Natural History in 1984. The valuable necklace was given to Mrs. Anna Case Mackay as a wedding gift by her husband Clarence H. Mackay - the American financier who inherited a $500 million estate from his father John W. Mackay, a silver miner turned telegraph mogul - when they got married in 1931.


Mackay Emerald Necklace Muzo Mine Colombia

©Smithsonian Institution


Characteristics of the gemstone

The Mackay Emerald is a 167.97-carat, oval cabochon-cut, deep grass-green colored emerald, with its horizontal and vertical diameters approximately equal to 2 ins. (5.08 cm). The diaphaneity of the stone is translucent, with light being transmitted through the stone, but its interior not being visible, probably because the stone is heavily included. The presence of inclusions in emeralds is a common feature, and characteristic of all natural emeralds.

The emerald which originated in the Muzo mines of Colombia is the largest faceted emerald in the National Gem Collection of the NMNH of the Smithsonian Institution. The emerald was set as the centerpiece of a square-shaped pendant with a platinum framework, whose edges were mounted with diamond baguettes. The upper end of the pendant has an emerald arch set with smaller rectangular-shaped emeralds, by which the pendant is suspended from the art deco diamond and platinum necklace. The pendant and necklace was designed by Cartier Inc. who sold the stunning piece of jewelry to Clarence H. Mackay in 1931.


History of the Emerald

The source of the emerald

The source of the Mackay Emerald is the ancient and historic Muzo mines, situated at the northwestern end of the NW-SE emerald belt in the Andes Mountains, known as the "Cordillera Oriental." The other two ancient and historic emerald mines are the the Coscuez mines situated a few kilometers north of the Muzo mines and the Chivor mines situated at the southeastern end of the emerald belt.


History of the exploitation of emeralds by the ancient Indian tribes

Archaeological evidence shows that the three mines the Muzo, Coscuez and Chivor had been exploited since ancient times, extending back to at least a 1000 years before Christ, by the indigenous Indian tribes of South America, such as the Incas, Aztecs, Toltec, Mayan and Chibchan tribes, who besides using emeralds as ornaments also considered them as sacred stones offering them to their Gods, and burying them with their dead. When the Spanish conquistadors reached Peru  and Mexico, in the early 16th century, they found the native Indians in possession of many large and beautiful emeralds, and in Mexico some of these emeralds were skillfully cut into characteristic shapes, such as flowers, fishes and other natural objects. The conquistadors whose main purpose in colonizing these lands was the plunder of its natural resources, lost no time in embarking on a extensive search to trace the origin of these beautiful emeralds, but were unsuccessful, simply because there had been no emerald deposits in Peru and Mexico at that time or even now. The Spanish were not aware that the source of these emeralds were actually neighboring Colombia, and the native Peruvians and Mexicans were not too keen in revealing this secret, as they feared the Spaniards would exploit these resources to the maximum and deplete them within a short period of time. Having been unsuccessful in locating the source of the emeralds in Peru and Mexico, the Spanish conquistadors went on a spree of desecrating the graveyards of the ancestors of the indigenous Indians, and their sacred places of worship, stripping them of their emeralds, and shipping large quantities of these emeralds back to Spain.


The Spanish Conquistadors locate the source of the South American emeralds

The Spanish conquistadors got an indication of the possible source of the South American emeralds for the first time in 1537, when Gonzalo Jimenez de Quesada, conquered the interior of Colombia, and entered the valley of Guacheta, when he was received warmly by the Chibcha Indian Chief, who gifted him with nine large emeralds. Gonzalo Jimenez immediately knew that the emeralds he received as gifts must have been sourced locally, and knowing fully well that the Chibcha Indians would not voluntarily reveal the source of these emeralds, assigned two of his Captains to form a team to explore the surrounding countryside to locate the source.  Eventually after more than an year's search, the two Captains were finally successful in locating the source in a wild inaccessible region high up in the Andes mountains, about 70 miles northeast of Bogota, the new capital city, founded by Gonzalo Jimenez. The soldiers found that the Indians worked in these mines mainly during the rainy season, and exploitation of the mines had been going on for a very long time. The area where the mines were located was known as Somondoco, which subsequently came to be known as Chivor. The Spaniards were successful in subduing the Chibchan Indians, and in spite of the inhospitable terrain and the inaccessibility of the region, began the exploitation of the Chivor mines. However, the incredibly cruel conditions under which the mines were operated, became so brutal and unbearable, that King Charles II of Spain, issued a royal decree in 1675, closing down the mines indefinitely. With the abandoning of the mines the surrounding jungle reclaimed the area and all traces of the Chivor mines were lost for over 200 years, until rediscovered in 1896, by the mining engineer Don Francisco Restrepo.


Discovery of the Muzo emerald mines and the history of its operation

Soon after the conquering and subjugation of the Chibchan Indians in 1537, the Spaniards attempted to conquer and subjugate the neighboring Muzo Indian tribe, a warlike tribe, but without much success. The Muzo Indians fiercely and successfully resisted the Spanish attempts at conquest for almost 20 years, but in the year 1555 was partially subdued by the Spanish under Luiz Lanchero, who in the same year founded the town of Villa de Santissima Trinidad de los Muzos, at the foot of the Itoco Mountains. It is said that the location of the town of Muzo was deliberately selected, the Spainsh having learnt that the nearby Itoco mountains had yielded emerald in abundance. In 1558, the Spanish began mining operations in the Itoco mountains, in spite of continued hostilities by the Indians. Operations were actively pursued for sometime in the face of repeated attacks by the Indians, but was later abandoned probably due to low production, and the area was overgrown with jungle and lost without any trace.

For the next 40 years the Spaniards were just groping in the dark unable to find the original Indian workings, without any co-operation from the indigenous tribes. Finally in the year 1594, the Spaniards were successful in locating the original Indian workings, close to the site of the present-day Muzo mines, about two and a half miles from the town of Muzo. The Spanish began mining operations in earnest and within the first 15 years a substantial output was obtained from these mines, the Spanish Crown taking a fifth of the output of these mines and the occasional spectacular finds from these mines. However, after this production began to decline rapidly, in spite of the fact that the Spanish Crown re-organized the industry under the direction of the Royal treasury. The main reasons attributed for this serious decline in production were compulsory labor imposed on the neighboring tribes, long working hours imposed on the workers, cruelty and maltreatment of workers; the combined effect of these harsh measures being high mortality rate among the working population, and the fleeing of the population from the region leading to depopulation. Other factors include dishonesty on the part of both workers and supervising officials, and the change from underground operations in galleries to open-cut operations.

The status quo prevailed until the middle of the 18th century, with little or no increase in production, until a disastrous fire in the mines put a stop to all mining activity and the mines were abandoned for a long period of time and recommenced production only after Colombia had gained its independence from the Spanish in 1819, and the ownership of the mines were transferred to the new-born republic. However, the new republican government lacked the organization and managerial skills needed for running the mines, but realizing the potential of the mines as a revenue generator, opted for private exploitation taking 10% of the profits. Accordingly, the mines were given out on lease to private companies from 1824 to 1848, until the Congress in Bogota decreed that all emerald deposits in the country should be worked under the direction of the nation. In spite of this decree the government seems to have entered into contracts with private parties as either partnerships or strict concessions. From 1848 to 1909, the Muzo mines were worked almost continuously, but the development of the mines suffered due to lack of a sustained policy of management, technical skills, and sound geological knowledge and advice.

In 1909, the Colombian Government signed a partnership contract to exploit the Muzo mines, with a British-based company, The Colombian Emerald Mining Company Ltd. controlled by South African diamond interests. The company using the knowledge, experience and technical skills gained by the exploitation of diamonds in South Africa, actively exploited the Muzo emerald deposits for a few years, but unfortunately the Government rescinded the contract and took over the sole control of the mines. However, following legal action taken by the company, the Government was forced to  pay damages to the company. Operations in the Muzo mines came to a complete standstill in January 1913, as the appropriations allocated by the Government was insufficient for re-establishing mining activity. Moreover the outbreak of World War I had a serious impact on the precious stone market that prevented the profitable exploitation of the mines. Production in the Muzo mines resumed after World War I, but the mines were again closed down in 1925, due to poor funding by the government. In 1933, the Muzo mines reopened under the direction of Peter W. Rainier, and an American group marketed production on a commission basis for the government. In 1946, the mining rights to the Muzo mines were sold by the government to Banco de Republica, Bogota, which ran the mine profitably until the end of 1947, but subsequently incurred losses for about an year from 1948 to 1949. Exploitation of the Muzo mines continued in the 1950s and 1960s, until in the year 1968 the government sponsored company ECOMINAS was granted authority to mine Muzo and also to buy stones from private parties as well as to cut and sell stones. Following a period of anarchy in the Muzo mines and other government mines between 1976 and 1977,  the Muzo mines were leased to the Sociedad de Mineros Boyancences for a ten year period. Since then the Muzo mines are leased by the government for 10-year periods. The Muzo mines are still under production, and the current lease is still held by the Sociedad de Mineros Boyancences. The Muzo mines were at one time the most prolific emerald mines in the world.


Characteristics of Muzo emeralds

Muzo emeralds generally have a deep herbal-green color. The transparency is good, due to scarce presence of gardens and inclusions. However, the Mackay Emerald seems to be an exception, as the stone is translucent, probably containing inclusions.

The Muzo emeralds have three-phase inclusions containing gas, fluid and crystals of halide. They also contain inclusions of calcite and yellow-brown needles of the mineral parisite. The specific gravity of the Muzo emeralds is 2.71 and the refractive index 1.578.


The Mackay Emerald exhibited at the 2001 Tucson Show

The Mackay Emerald Necklace was exhibited by the Smithsonian Institution, at the 47th annual Tucson Gem and  Mineral Show held in February 2001, and hosted in the Tucson Convention Center by the Tucson Gem and Mineral Society. The theme for the TGMS Main Event Show, was "Minerals from Russia" and featured about 40 special exhibits and 70 guest exhibits, in addition to about 240 retail dealers who also play an important part in this event. Several educational seminars and symposia relevant to the annual theme in which specialists in the field of geology and mineralogy took part, were also held in parallel, during the course of the main event. Numerous examples of fine and amazing mineral specimens from Russia and the former Soviet Union were on display in the convention center, which supplemented the theoretical information presented by the Russian experts at the seminars. But undoubtedly, the star attraction of the Russian exhibits was the collection of Faberge objects from Tsarist Russia, which were masterpieces of artistic and bejeweled objects, created by Faberge, on commissions from the last imperial family headed by Tsar Nicholas II.

The Mackay Emerald Necklace belonging to the National Gem Collection of the Smithsonian Institution, was displayed in its own dedicated case diligently guarded by its own dedicated Tucson police officer.


The Mackay Emerald Necklace exhibited at the 2006 Denver Mineral Show

The annual Denver Mineral Show held in mid-September, is the second largest mineral, fossil and gem show, held annually in the United States of America, after the Tucson Gem and Mineral Show, which is held in February, and similar to the Tucson Show, the Denver Mineral Show also consists of a main show and several satellite shows.

The Main Denver Show that was held from 15th to 17th September 2006, was actually divided into three different shows held separately in three halls of the Merchandise Mart. The first of these "The Denver Gem and Mineral Show" was held in the Expo Hall area. The second show, "The Colorado Fossil Expo" was held in the Plaza Annex. The third show, "The Gem and Jewelry Show" was held in a third hall under tight security conditions with restricted entry allowing only dealers with resale licenses.

The Denver Gem and Mineral Show was held in the spacious and well-lit Expo Hall of the Merchandise Mart, with corridors running off one side, lined with rooms occupied by different mineral dealers. The theme of the Main Denver Show in 2006 was South America. In keeping with this theme, museums from around the world and the United States had displayed exhibits that were arranged in a row in the center of the Expo Hall. The National Museum of Natural History of the Smithsonian Institution had brought in their fabulous Mackay Emerald Necklace, with the 167.97-carat Mackay Emerald of Colombian origin mounted as the centerpiece of a pendant to an art deco diamond and platinum necklace.

The "Colorado Fossil Expo" that was hosted in the adjacent Plaza Annex, attracted around 50 dealers specializing in fossils, meteorites, petrified wood etc. The most impressive of the exhibits in this section were of course the skeletons of the giant dinosaurs.

A parallel satellite exhibition held between the 12th to 17th September, at the Holiday Inn Central  was the Colorado Mineral and Fossil Show, in which 200 international dealers participated, and was spread over three floors of the hotel, the foyer as well as the ballroom.


A short biography of Clarence H. Mackay

Clarence H. Mackay who was born on April 17, 1874, was an American financier who inherited a $500 million estate in 1902, from his father John W. Mackay, a silver miner who later became a telegraph mogul, the owner of the telegraphic company IT & T. In 1898, Clarence married Katherine Duer, the 18-year old beautiful debutante from a high society New York family, whom he met previously and fell in love while crossing the Atlantic in a steamship in 1897. After their marriage Clarence and Katherine settled down in Harbor Hill in Roslyn, Long Island, where they built a large mansion designed by Stanford White, overlooking the Hempstead Harbor.

Clarence Hungerford Mackay

Clarence Hungerford Mackay

The couple had three children by this marriage, but unfortunately Katherine decided to elope with her husband's physician Dr. Joseph Blake in 1910, leaving behind Clarence and her three children. The marriage ended in divorce in 1914.

In 1916, Clarence H. Mackay fell in love with Anna Case of Clinton, New Jersey, the daughter of a blacksmith, who had a natural talent for music and became a lyric Soprano singing with the Metropolitan Opera, after her performance at a private musicale given in his house. But, probably because of religious convictions Clarence Mackay would not remarry as long as his first wife lived. In 1930, Katherine returned to New York from Paris, where she had been living ever since she left Clarence, and tried to make up with her former husband, but tragically died the same year of cancer. After Katherine's death, Clarence and Anna got married at St. Mary's Roman Catholic Church in Rosalyn, New York, in 1931. On the occasion of this wedding Clarence gifted to Anna an emerald and diamond necklace set in platinum. The 167.97-carat emerald that was mined in Colombia, was set as the centerpiece of a pendant to a diamond and platinum necklace designed by Cartier.

Anna Case Mackay

Clarence and Anna were completely devoted to each other, and friends who were close to the couple, admired Anna's devotion to her husband, helping him cope with his financial difficulties in the early 1930s, and his ill health during the last two years of his life. Clarence H. Mackay died in November 1938. Anna had no children by her marriage to Clarence, but she became stepmother to her husband's three children from his first marriage. Anna Case established the "Anna Case Mackay Award" to provide support for the careers of aspiring singers through the Santa Fe Opera. Anna Case lived up to the ripe old age of 96 years and died in the year 1984. At her death she bequeathed two of her most expensive necklaces, which included the emerald and diamond necklace, given as a gift by her late husband Clarence, and which she cherished for a life time, to the Natural History Museum of the Smithsonian Institution. The emerald and diamond necklace subsequently came to be known as the Mackay Emerald Necklace.

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1.The National Gem Collection - Jeffrey E. Post   
2.The Emerald Deposits of Muzo, Colombia - Joseph E. Pogue - Transactions of the America Institute of Mining Engineers. Vol. LV 1917. 
3.GEO347K GEM NOTES - Beryl, Department of Geology, University of Texas, Austin-Website
4.Alluvial Exploration and Mining - Precious Stones, Emerald -  Rafal Swiecki  
5.Clarence H. Mackay - Wikipedia, the free encyclopedia 








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